Nanomaterials doi: 10.3390/nano16211441

Authors: Gül Bayram Sevda İldan Özmen Taylan Bozok Nuran Delialioğlu

Background: In this study, we aimed to synthesize zinc oxide nanoparticles (ZnO NPs) using aqueous extracts of fresh and dried Rumex acetosa leaves and characterize their physicochemical properties and antibacterial activities. Methods: Nanoparticles were characterized using UV–Vis, FE-SEM, EDX, DLS, zeta potential measurements, XRD, and FT-IR spectroscopy. Antibacterial activity was evaluated against five bacterial reference strains using a resazurin microdilution assay to determine minimum inhibitory concentrations (MICs). Results: ZnO NPs from both extracts were spherical and had a hexagonal wurtzite structure. For the fresh and dried leaf preparations, respectively, particle sizes were 12–23 and 19–46 nm, hydrodynamic diameters were approximately 51 and 69 nm, and zeta potentials were approximately −24 and −14 mV. Both samples showed characteristic ZnO UV absorption, band gaps of 3.17 and 3.15 eV, respectively, and Zn–O stretching near 435 cm−1. EDX detected carbon in the fresh leaf preparation. Both preparations inhibited all tested bacteria, with MICs ranging from 14.20 to 113.64 µg/mL for fresh leaf and from 7.10 to 113.64 µg/mL for dried leaf preparations. Conclusions: Dried leaf extract-derived ZnO NPs may be evaluated for photocatalysis, UV protection, and sensing, while the antibacterial activity of fresh leaf extract-derived ZnO NPs suggests potential for coatings, wound dressings, and food packaging.

Nanomaterials doi: 10.3390/nano16211440

Authors: Xiangong Zhou Manhui Liu Xiancheng Zhou Weikang Kong

Macroscopic fracture testing of nano-modified cement paste requires the labor-intensive fabrication of notched beams. This study establishes a micro-to-macro surrogate modeling framework mapping localized nanomechanical scratch signatures to macroscopic fracture resistance. A database was compiled for pure Portland cement paste (w/c = 0.30, 28-day curing) across seven nano-silica (NS) dosages (0.0–3.0%). Across 21 independent physical beam specimens (Nmacro = 21) and 470 validated phase-segmented nanoscratch observations (Nmicro = 470), localized descriptors were acquired across unhydrated clinker, hydration products, and the clinker–hydrate interfacial transition zone (micro-ITZ). Within a leak-free pipeline, an XGBoost surrogate model was trained using specimen-grouped nested cross-validation (Nested GroupKFold), achieving cross-validated R2 values of 0.878 ± 0.024 (95% CI [0.834, 0.919]) for macro-fracture toughness (\(K_{\text{IC}}^{\text{macro}} \))  and 0.865 ± 0.028 (95% CI [0.815, 0.912]) for fracture energy. (Gf). Leave-one-dosage-out validation demonstrated that when provided with the target mix’s in situ nanoscratch fingerprint, the model successfully tracked the non-monotonic fracture evolution, including the peak at 2.0% NS and the agglomeration degradation at 3.0% NS. Bootstrap Tree-SHAP attribution identified interfacial micro-toughness (\(K_{\text{IC},\text{ITZ}}^{\text{micro}} \)) as the primary predictive contributor (42.5% [95% Cl: 37.8%, 47.1%], revealing a model-suggested transition region around 0.80 MPa m1/2 above which interfacial crack resistance associates with substantial macroscopic toughening. This framework provides an efficient surrogate approach for evaluating macro-fracture properties from micromechanical indicators.

Nanomaterials doi: 10.3390/nano16211438

Authors: Talal A. Almohaya Salman Alrokayan Tajamul Hussain

Due to their well-documented robust antibacterial properties, silver nanoparticles (AgNPs) are commonly used in wound dressings to prevent bacterial infection. β-sitosterol (BST), a plant-derived phytosterol, further supports wound healing processes through its antioxidant, anti-inflammatory, and proangiogenic properties. In this study, we constructed a novel delivery system for its potential use in wound healing. Polyvinyl alcohol/chitosan (PVA/CS) nanofibers were prepared incorporating both BST and AgNPs by electrospinning method. This synthesized PVA/CS/AgNPs/BST nanofiber system was found to comply with the desired size, morphology, encapsulation efficiency, and time course of release for incorporated components, as confirmed by SEM, TEM, FTIR, HPLC, and XRD analyses. Zone of inhibition (ZOI) test revealed a significantly greater bacterial growth inhibition for constructed nanofiber systems than for AgNPs alone or PVA/chitosan blank fibers. Individually, AgNPs and AgNPs + BST demonstrated significant antibacterial activities against Staphylococcus aureus strains ATCC 29213, 43300, and BAA-977, with minimum inhibitory concentration (MIC) values of 62.5, 62.5, and 31.2 µg/mL, respectively. Likewise, AgNPs and AgNPs + BST showed antibacterial activities with MICs of 31.2 µg/mL and 15.6 µg/mL against Pseudomonas aeruginosa strains ATCC 27853 and MDR-7067 respectively. In contrast, no bacterial growth inhibitory effects were noted for BST against any of the studied bacterial strains. Compatibility analysis revealed that HFF1 cells treated with AgNPs and AgNPs + BST showed no cytotoxic effect at least up to concentrations of 15.6 µg/mL and 31.2 µg/mL, respectively, whereas BST alone had no effect on cell viability, even at higher concentrations. Collectively, these data show that the PVA/chitosan/AgNPs/BST system exercised a greater bacterial growth inhibitory effect against both Gram-positive and Gram-negative bacteria, underscoring its potential application in wound healing, subject to its in vivo validation.

Nanomaterials doi: 10.3390/nano16211439

Authors: Azat Abdullaev Rustem Tlegenov Magomed A. Umakhanov Jacques O’Connell Abubakar M. Ismailov Kairolla Sekerbayev Zhandos N. Utegulov

Controlling heat flow in beta-gallium oxide (β-Ga2O3) thin films requires understanding both phonon transport within the semiconductor and heat transfer across metal/semiconductor interfaces. Here, we investigate these pathways in high-temperature radio-frequency magnetron-sputtered β-Ga2O3 films grown on c-plane sapphire with thicknesses from 0.42 to 2.1 μm. The thermal conductivity increases from 5.4–6.9 W m−1 K−1 in the 420 nm film to approximately 10–12 W m−1 K−1 in the thicker films. Structural characterization reveals thickness-dependent microstructural evolution, including grain coarsening and intergranular void-like defects. An analytical Debye–Klemens model incorporating phonon scattering from film boundary and defects reproduces the overall thickness dependence. The Ar plasma-treated samples exhibit Al/β-Ga2O3 thermal boundary conductance values of approximately 100 MW m−2 K−1, about 70% higher than the untreated sample (~60 MW m−2 K−1), while the thermal conductivity of the underlying films remains within a comparable range. Picosecond acoustic measurements, transmission electron microscopy and electron energy loss spectroscopy reveal a corresponding modification of the interfacial acoustic response and formation of an ultrathin amorphous/disordered near-surface region. Although variations between independent deposition runs cannot be excluded, these findings suggest that thickness-dependent microstructure and plasma-associated interface modifications offer promising approaches to tailoring thermal transport in β-Ga2O3-based devices.

Nanomaterials doi: 10.3390/nano16211437

Authors: Yihan Wu Jingyi Zhang Yukui Rui

Engineered nanomaterials (ENMs) can regulate crop photosynthesis, but the same nanoparticle may stimulate or inhibit carbon assimilation depending on dose, material properties, delivery route, and crop species. Existing reviews largely treat crops as interchangeable and report rather than predict effects. This review organizes the evidence around the C3/C4 photosynthetic distinction. We contrast C3 and C4 architectures, and CO2-limited, photorespiration-prone C3 leaves versus Kranz-type, CO2-concentrating C4 leaves and synthesize how metal-based nanoparticles, carbon dots, and nanofertilizers affect light harvesting, electron transport, Calvin-cycle enzymes, stomatal behavior, and source–sink relations, separating direct interactions from nutrient-, water-, and redox-mediated indirect effects. Head-to-head C3–C4 trials remain uncommon, yet those that exist point the same way: the two groups move in one direction within a given experiment, differing only in how large the movement is. The administered dose is also a poor guide to the dose that actually reaches a chloroplast. As the dose rises, plants pass through a sequence—no response, adaptive signaling, physiological stress, and finally harm. Whether the outcome is positive or negative is governed by material and dose rather than by photosynthetic type; the latter changes only the strength of the response. These observations suggest tentative rules: C3 crops are best served by ENMs aimed at CO2 supply and photorespiration, whereas C4 crops benefit more from ENMs targeting electron transport, sink strength, and stress. The way forward lies not in inventing still more materials but in standardized, physiology-informed designs that let the field predict responses instead of merely cataloging them.

Nanomaterials doi: 10.3390/nano16211436

Authors: Qi Zhao Zhipeng Yao Yusheng Niu Xiangjie Guo Kunpeng Cui

Growing global concern over soil salinization has drawn considerable attention to the remediation and amelioration of saline–alkali soils. Coal gangue (M) can be applied to improve saline–alkali soils; nevertheless, its amelioration performance is subject to certain limitations. Organically modified coal gangue (GM) was prepared using alcohol ethoxylate-7 (AEO-7) as the primary modifier, and both M and GM were mixed with a saline–alkali soil at 10%, 20%, 30% and 40% (w/w) in a 28-day incubation and a 28-day soybean pot experiment. At 28 d, compared with the CK group, the GM40% treatment significantly increased the available potassium and alkali-hydrolyzable nitrogen in the saline–alkali soil by 49.91% and 97.10%, respectively, and increased soil organic matter by 10% compared with M40%. The GM groups decreased soil pH relative to CK, alleviated M-induced available phosphorus deficiency, and increased soil urease, peroxidase and catalase activities by 467.77%, 140.37% and 76.29%, respectively. Plant height, shoot dry weight and root dry weight increased by 23.24%, 102.22% and 208.05%. Amplicon sequencing showed that the modified material increased bacterial richness and shifted bacterial community composition. Thus, the organically modified gangue improved soil nutrient pools and soybean performance relative to raw gangue.

Nanomaterials doi: 10.3390/nano16211433

Authors: Chang-Mou Wu Min-Hui Chou Wun-Yuan Zeng

The journal retracts the article titled “Piezoelectric Response of Aligned Electrospun Polyvinylidene Fluoride/Carbon Nanotube Nanofibrous Membranes” [...]

Nanomaterials doi: 10.3390/nano16211435

Authors: Jihua Chen

Nanotechnology has shifted from demonstrating control over matter at the scale of a few billionths of a meter to building products that should work reliably and safely in clinics, factories, and the environment [...]

Nanomaterials doi: 10.3390/nano16211434

Authors: Maiby Valle Orta Edgar Cuara Alfonso Mercado Enrique Díaz Barriga Castro Pablo González Morones Marcos Granda Diego Martínez Patricia Álvarez Uriel Sierra

The conversion of industrial carbon wastes into functionalized graphene materials represents an attractive strategy for the sustainable production of advanced carbon nanomaterials. In this work, a graphitized coke-like waste generated during metallurgical coke production was evaluated as a precursor for the preparation of graphene oxide (GO) and amine-functionalized graphene oxide, using a commercial synthetic graphite as a reference material. Prior to oxidation, both graphites were subjected to a mild aqueous liquid-phase exfoliation (LPE) treatment employing water as the sole processing medium. Graphene oxides were subsequently prepared using a modified Hummers method and functionalized with n-octylamine through an ultrasound-assisted reaction. X-ray diffraction confirmed the successful conversion of both graphitic precursors into graphene oxide through the appearance of the characteristic (001) reflection at approximately 10–11° (2θ). Structural characterization revealed that the LPE treatment promoted partial delamination of the graphitic crystallites while preserving graphitic crystallinity. FTIR and thermogravimetric analyses indicated that LPE modified the distribution and accessibility of oxygen-containing functionalities generated during oxidation. After amination, the LPE-derived materials exhibited more pronounced spectroscopic and thermal changes, suggesting a greater participation of reactive oxygen-containing groups during functionalization. The results demonstrate that graphitized coke waste can be transformed into graphene oxide and nitrogen-functionalized graphene materials with characteristics comparable to those obtained from commercial graphite, providing a simple and sustainable route for the valorization of industrial carbon residues into value-added graphene-based material.

Nanomaterials doi: 10.3390/nano16211432

Authors: Mohammed Al Bahri Salim Al-Kamiyani David Laroze Alexis Matheu Tamara González-Vega Eduardo Saavedra Felipe Tejo

Magnetic skyrmions are promising information carriers for nanoscale spintronic devices, but their use in confined structures requires control of both topological survival and current-driven motion. We investigate perpendicular magnetic anisotropy engineering in a Z-junction nanotrack using micromagnetic simulations. The anisotropy is varied from 0.70 to 1.00 MJ/m3 at 300 K for a junction depth of 50 nm, junction width of 5 nm, and pulsed current density of 1.8 × 1012 A/m2. Five independent thermal realisations are considered for each finite-temperature condition. No annihilation is observed for Ku = 0.70–0.90 MJ/m3 during the 63 ns observation interval, whereas all five realisations at 0.95 and 1.00 MJ/m3 undergo annihilation within approximately 9–10 ns. The 0.90 MJ/m3 case remains topologically intact despite strong compression. Additional in-plane mesh refinements reproduce survival at 0.90 MJ/m3 and annihilation at 1.00 MJ/m3. The selected compact reference condition Ku = 0.85 MJ/m3 is then examined from 0 to 500 K, with a deterministic reference at 0 K. The trajectories show preservation of the skyrmion-like topological state within the available observations, together with temperature-dependent positional, radial, and velocity variations. These results distinguish finite-time topological survival from dynamical reproducibility. The temperature sweep describes thermal-noise effects within a fixed-parameter model; it does not establish a thermally activated lifetime, a universal optimal anisotropy, or an experimental device operating-temperature range.

Nanomaterials doi: 10.3390/nano16211431

Authors: Luis Humberto Robledo-Taboada Fernando Chiñas-Castillo Magdaleno Caballero-Caballero Rafael Alavez-Ramírez Jesica Ariadna Jiménez-Mendoza José Raúl Pérez-Higareda Irving Néstor Sierra-Sánchez Reynier Suárez Martínez Laura Elvira Serrano de la Rosa

This review examines silicon surfaces produced by femtosecond laser microstructuring and electrochemical etching, as well as their sequential integration. Laser processing creates multiscale topographies, including laser-induced periodic surface structures (LIPSS), conical features, and craters, whereas electrochemical etching generates porous silicon with tunable pore dimensions and high surface area. The central focus is the process coupling between these techniques: how laser-generated topography, defects, and modified surface chemistry may influence subsequent electrochemical dissolution, and how etching, in turn, may alter the stability and wetting of the laser-defined architecture. Available studies demonstrate substantial changes in morphology, roughness, and contact angle after sequential processing, but do not yet establish universal synergistic enhancement or self-cleaning performance. Accordingly, this review distinguishes experimentally demonstrated process-integration effects from mechanistic hypotheses and future design targets. It also evaluates evidence limitations related to durability, mechanical stability, scalability, reference accuracy, and application-specific validation, with particular attention to conceptual sensing platforms based on hierarchical silicon surfaces.

Nanomaterials doi: 10.3390/nano16211429

Authors: Biliang Zhang Jiejun Yuan Haidong Zhang Wei Xu Yongmei Wang Leiying Han Xiaoyan Liu

Water-based, wax-free release agents are attractive for concrete formwork, yet their emulsification window and demoulding behaviour remain poorly defined. This work prepared a soybean-oil/naphthenic-oil emulsion and evaluated its stability and pull-off performance. OP-10/Span-80 blends produced a visually stable soybean-oil emulsion in a narrow hydrophilic–lipophilic balance (HLB) window, with only trace or small separation within 1 h across a calculated HLB interval of 12.15–12.31 at an assumed OP-10 HLB of 14.5 (11.3–12.3 across the reported range). The high-non-volatile-content naphthenic-oil emulsion containing 1.00 wt% sodium benzoate (MH2+) showed no visible phase boundary after centrifugation at 7000 rpm for 6 min and only a thin re-emulsifiable surface layer after 20 d, whereas the sodium-benzoate-free emulsion separated into three phases. At 1.57–1.59 micrometres, the 1:3 blend of the soybean-oil emulsion and MH2+ gave a pull-off force of 7.92 N, comparable to EP6 (7.963 N at 1.50 micrometres) and lower than MH2+ (11.63 N) and the soybean-oil emulsion (55.26 N), and produced visually more uniform demoulded surfaces. The blend force increased to 73.68 N at 1.05 micrometres, indicating that sufficient coating is essential. The 1:3 blend is therefore a promising low-force, wax-free water-based release agent at sufficient coating, providing a basis for coating optimization and field validation.

Nanomaterials doi: 10.3390/nano16211430

Authors: Shun Zhou Qi Zhang Fangwei Han

Altermagnets combine compensated magnetic order with momentum-dependent spin splitting, offering spin-polarized states without stray fields. Plasmons in altermagnetic metals can carry a spin signal, but its distribution among the modes of coupled layers is unknown. Here, we study a Coulomb-coupled bilayer of the d-wave altermagnet RbV2Te2O, using a representative four-band tight-binding model with spin–orbit coupling and the random-phase approximation with density-channel Coulomb interaction. We find that, at equal filling in a symmetric environment, switching the relative magnetic domain leaves the charge spectra unchanged but exchanges the total-spin weight between the acoustic (187.4 meV) and optical (413.1 meV) plasmons at q = 0.2 nm−1. A missing spin peak arises from interlayer cancelation, which the layer-difference spin reveals, or from a symmetry node along the diagonal, where both spin channels vanish. Raising the chemical potential from 0 to 0.2 eV softens the acoustic plasmon by 15% and raises the relative spin amplitude, as the xy orbital loses low-energy current weight. With a dynamic hexagonal boron nitride (hBN) spacer, the plasmons move to 214.0 and 409.3 meV; the selection survives, and only about 2% leaks into the dark branch. Charge spectra are domain-independent, so testing requires a spin-sensitive probe.

Nanomaterials doi: 10.3390/nano16211428

Authors: Camellia Panatarani Karisa A. Fauzi Ferry Faizal Adi Darmawan Nur L. Hamidah Eka C. Prima Mia Miranti Yolani Syaputri Bhawana Jain Sundoro Y. Azhary I M. Joni

In molecular biology, magnetic nanobeads play a key role in the separation and purification of DNA and RNA, which are necessary for procedures such as PCR. However, conventional magnetic nanobeads suffer from instability, aggregation, and poor surface functionality. The objective of this study was to synthesize and characterize graphene oxide (GO) -conjugated Fe3O4@SiO2 magnetic nanobeads for DNA isolation. The large surface area and functional groups of GO could bring about strong interactions with DNA, thus enhancing the binding and separation efficiency. Here, Fe3O4 nanoparticles are chosen as the core material because of the high magnetic saturation and biocompatibility. The silica shell can improve stability and serve as a platform for further functionalization. Amino functionalization of Fe3O4@SiO2 allows conjugation of GO at reactive sites. The stability and functionalization of the nanobeads were confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size distribution, zeta potential, and electrophoretic mobility. The optimal GO to Fe3O4@SiO2-NH2 conjugation ratio (5:1) balanced adequate GO coverage and controllable particle dimension. The increased negative charge improved colloidal stability and reduced aggregation. The enhanced electrophoretic mobility ensures efficient separation of DNA. These findings highlight the potential of GO-conjugated Fe3O4@SiO2 magnetic nanobeads as promising tools for advanced DNA separation techniques.

Nanomaterials doi: 10.3390/nano16211427

Authors: Peilun Wang Lei Wang Xinyu Zhang Yinlong Kuang Shuming Liu Le Cui Yixue Xu Qiufang Yao

Enrofloxacin (ENR), a widely used veterinary fluoroquinolone, persists in the environment and resists conventional treatment. A metal-free nitrogen-doped carbon catalyst (N@C) was synthesized from graphitic carbon nitride (g-C3N4) and glucose via hydrothermal compositing and carbonization at 900 °C, and used to activate peroxymonosulfate (PMS) for ENR degradation. TEM, XRD, XPS, Raman spectroscopy, and N2 physisorption revealed a hierarchically porous architecture with a specific surface area of 578.6 m2 g−1 and 10.2 at% nitrogen. The N@C/PMS system removed over 99.9% of ENR in 20 min ([ENR]0 = 20 mg L−1, [PMS] = 0.2 mM, [N@C] = 5 mg L−1, 25 °C), with a rate constant of 0.4389 min−1. TOC removal reached 40% within 30 min at 1.0 mM PMS, and post-reaction XPS and XRD showed a preserved framework. Quenching tests, DPA probing, solvent isotope effects, and electron spin resonance (ESR) spectroscopy indicate a non-radical pathway dominated by singlet oxygen (1O2), initiated by heterolytic cleavage of the PMS peroxide bond at graphitic N sites. The catalyst retained >95% of its activity after four cycles and >93% removal in tap, river, and lake water. These findings provide a mechanistic basis for designing metal-free, matrix-tolerant persulfate activation systems for fluoroquinolone wastewater treatment.

Nanomaterials doi: 10.3390/nano16211426

Authors: Rojoba Yasmin Jabia Mostofa Chowdhury Sultana Razia Akhter Sk. Md. Golam Mostafa

Two-dimensional (2D) nanomaterials offer promising properties for energy storage, drug delivery, and environmental remediation, but their performance can be limited by aggregation, restacking, and challenges in controlling morphology and surface properties. Surfactants provide versatile tools for addressing these limitations through surface adsorption, template-directed growth, exfoliation, and dispersion stabilization. This review critically examines how surfactant-assisted strategies influence the synthesis, morphology, interfacial properties, and stability of 2D nanomaterials and how these changes relate to application performance. Representative studies are considered across drug delivery, energy storage, and environmental remediation, with attention to reported outcomes such as pollutant adsorption, oil–water separation, electrical conductivity, and photocatalytic activity. Where available, quantitative results are compared across representative studies, highlighting reported performance improvements and the limitations of cross-study comparisons. The review also distinguishes the direct effects of surfactant–material interactions from performance changes associated with morphology, surface chemistry, defects, and interlayer structure. Practical surfactant selection requires balancing dispersion and structural control against potential active-site blockage, impaired charge or ion transport, purification demands, environmental concerns, and production costs. Residual surfactants, inconsistent processing, limited reproducibility, and scalability remain important challenges. By connecting processing mechanisms with application outcomes and practical limitations, this review identifies priorities for more systematic surfactant selection, improved process control, and environmentally responsible, reproducible production of 2D nanomaterials.

Nanomaterials doi: 10.3390/nano16211425

Authors: Panagiota V. Polydoropoulou Vasilis N. Burganos

Sonication of carbon nanotube (CNT) dispersions is commonly employed in practice to disentangle agglomerates in order to promote homogeneity and finer dispersion in suspensions and, consequently, to effect more predictable end-properties of nanofluids and nanocomposites. Sonication also influences CNT morphology in terms of shape and length, affecting, in turn, the thermal performance of the resulting medium. Although sonication is generally known to improve heat transfer, increased sonication times may have adverse results due to CNT buckling and scission and, thus, shortening of the CNTs. The present work aims to quantify the distinct effects of sonication-induced structural changes on the thermal conductivity and the evolution of this relationship in time through a dual-scale simulation approach. The simulator reconstructs three-dimensional (3D) assemblages of CNTs with prescribed agglomeration density, CNT length and curvature, evaluates the thermal conductivity locally and temporally within a representative volume element (RVE), and integrates the results into a macroscopic model to extract the effective conductivity as a function of sonication time. The numerical simulations are compared with experiments that follow the thermal conductivity as a function of sonication time. The results elucidate the separate but also the synergistic influence of the agglomerate microstructure on the effective thermal conductivity, paying particular attention to CNT curvature, length and agglomeration features. It is found that the internal density of the agglomerates is of major significance for the heat conduction process, followed by CNT length and curvature.

Nanomaterials doi: 10.3390/nano16211424

Authors: Ankit Kumar Jeyavel Velmurugan Jae Shin Roshni Ramakrishnan Bryan Buckalew

Cu–Cu hybrid bonding at reduced thermal budgets depends critically on reliable grain intermixing across the bonding interface. Yet interfacial evolution is still predominantly assessed qualitatively, precluding objective comparison across copper microstructures and process conditions. Here, we introduce Bond IQ, an automated image-based metrology framework that converts registered cross-sectional FIB-SEM datasets into physically interpretable descriptors using classical computer-vision methods. We apply the framework to five blanket chip-level pairings spanning three engineered copper microstructures: coarse-grain (CG), fine-grain locked (FG-L), and fine-grain thermally dynamic (FG-TD) Cu, thermocompression bonded at 210 °C for 2 h. Three coupled but distinct metrics are extracted: Bridged Interface Fraction (BIF), Interface Void Loading (IVL), and normalized Grain Penetration Depth (GPD). The symmetric CG/CG interface exhibited the weakest evolution, combining high IVL (5.4 nm) with low BIF (6.1%) and low GPD (0.20). By contrast, CG/FG-TD achieved the highest BIF (54.5%) at low IVL (0.6 nm), signifying broad but comparatively shallow bridging, whereas CG/FG-L reached the highest GPD (0.89) at moderate BIF (32.7%), indicating localized yet deeper directional grain advancement. Among symmetric fine-grained interfaces, FG-L/FG-L displayed the lowest IVL (0.5 nm), underscoring the role of fine-grain stability in void suppression. Collectively, these results demonstrate that interface bridging, void elimination, and penetration depth are governed by distinct but interrelated contributions of grain-size contrast and microstructural stability. By reducing subjective interfacial assessment to quantitative, mechanistically interpretable descriptors, Bond IQ offers a scalable route to screen copper microstructures and bonding conditions, and it can be extended to other metal–metal interfaces where microstructural evolution governs low-temperature bonding reliability.

Nanomaterials doi: 10.3390/nano16211423

Authors: Xiao-Chun Wang Xilian Jin

Since the experimental isolation of single-layer graphene in 2004 [...]

Nanomaterials doi: 10.3390/nano16211422

Authors: Yu Zhang Jiale Wang Haotian Liu Yishuo Wang Guangjie Liu Wei Liu

Understanding and predicting the structure–property relationships in magnetic clusters remain challenging due to the complex interplay between geometry, electronic structure and spin configurations: density functional theory suffers from prohibitive computational cost for large-scale exploration, while existing graph neural networks struggle to balance long-range magnetic correlation capture, topological fidelity and scalability. We present MagCluster-GMAF, a physics-inspired hybrid graph architecture with magnetic cluster-aware serialization to preserve topological and electronic similarity during graph-to-sequence transformation, paired with a dual-branch design combining a Mamba-2 backbone for efficient long-range spin correlation modeling and a lightweight attention module as topological compensation. On a 2D doped magnetic material dataset, it achieved a total magnetic moment prediction MAE of 0.2683 μB, reducing the prediction error by 9.5% relative to the GPS + Transformer baseline and outperforming Graph-Mamba; at the 1400-node scale, it cut the GPU memory consumption by over 70% versus standard graph transformers while exhibiting near-linear empirical scaling at the studied graph scales. SHAP-based feature attribution analysis further identifies the key physicochemical descriptors governing the predictions, providing an effective approach for nanoscale magnetic material screening and the high-throughput screening of spintronic materials.

Nanomaterials doi: 10.3390/nano16211420

Authors: Sónia Simões Beatriz S. Monteiro Alexandra C. Alves

Carbon nanotube (CNT)-reinforced copper nanocomposites have attracted significant interest as multifunctional materials combining high electrical conductivity with enhanced wear resistance. In this work, Cu-CNT nanocomposites were fabricated using a powder metallurgy route and systematically investigated to establish the relationship between microstructure, tribological behaviour, and electrical performance. The materials were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) to evaluate CNT distribution and its influence on the copper matrix. Wear tests were performed to assess the functional performance of the composites. The results show that CNT incorporation significantly improved the wear resistance of copper, leading to reduced material loss and modifications in the dominant wear mechanisms. The enhanced tribological behaviour was associated with the reinforcing effect of CNTs, improved load transfer, and surface protection during sliding. Microstructural analyses revealed that CNT addition influenced the evolution of the copper matrix, contributing to improved durability. Importantly, the composites retained high electrical conductivity despite the presence of the nanoscale reinforcement. These results demonstrate the potential of Cu-CNT nanocomposites for conductive components operating under wear conditions and provide further insight into the microstructure-property relationships governing their multifunctional performance.

Nanomaterials doi: 10.3390/nano16211421

Authors: Felicia Stan Stefanut Ciochina Ionut-Laurentiu Sandu Catalin Fetecau

Understanding the time-dependent viscoelastic behavior of polymer carbon nanotube (CNT) nanocomposites is crucial for predicting their performance, particularly in load-bearing applications where the nanocomposites can be exposed to either short- or long-time loadings. In this study, the stress relaxation behavior of ethylene-vinyl acetate (EVA)–CNT nanocomposites containing 1, 3, and 5 wt% CNTs was experimentally investigated under load- and strain-controlled uniaxial relaxation conditions and modeled using the generalized Maxwell linear viscoelastic model. The results indicate that in the linear viscoelastic domain, the EVA–CNT nanocomposites retain at least 70–80% of their instantaneous modulus, and the equilibrium modulus almost doubled with increasing nanotube content from 1 to 5 wt%, yielding a 1.70- to 1.85-fold increase depending on the initial strain and relaxation period. When the strains exceed the viscoelastic limit (10–25%), all nanocomposites relaxed to about 65–70% of the initial stress. The generalized Maxwell model accurately captured the relaxation behavior of EVA–CNT nanocomposites within the linear viscoelastic domain, providing a robust fit for experimental relaxation data with relative errors not exceeding 5%. This study expands the potential application of EVA–CNT nanocomposites in engineering by providing insights into their stress relaxation behavior under both small and large deformations while highlighting areas for future improvement.

Nanomaterials doi: 10.3390/nano16211419

Authors: Sayma Adriana Rodriguez-Montelongo Arleth Miranda-Lopez Mariana Sanchez-Gil Lourdes Betancourt-Mendiola Veronica Perez-Luna Mauricio Comas-Garcia Mariano J. Garcia-Soto Sergio Rosales-Mendoza Omar Gonzalez-Ortega

Layered double hydroxides (LDH) are promising nanocarriers for vaccine delivery due to their biocompatibility and tunable surface properties. This study evaluated LDH and surface-functionalized derivatives containing amino (LDH–NH2) and carboxyl (LDH–COOH) groups as delivery platforms for a recombinant Zika virus (ZIKV) antigen (rpZDIII). The nanoparticles were synthesized by coprecipitation/hydrothermal treatment and afterward functionalized via silanization and succinylation. Their physicochemical characterization included hydrodynamic size, ζ potential, point of zero charge, and amine concentration, along with Fourier-transform infrared spectroscopy and thermogravimetric analyses. Protein adsorption was evaluated using bovine serum albumin, α-chymotrypsin, and the recombinant antigen rpZDIII. Cytotoxicity and immunogenicity were evaluated in HEK-293T cells and BALB/c mice, respectively. The functionalization affected the protein adsorption capacity and its retention after washing. The adsorption of rpZDIII was best described by the Freundlich model, with LDH–NH2 having the highest antigen adsorption and retention. All three formulations maintained high cell viability at lower nanoparticle concentrations (12.5–50 μg/mL). Immunization studies demonstrated that all nanoparticle formulations elicited strong antibody responses against rpZDIII; however, only unmodified LDH-induced antibodies were able to bind the full-length recombinant ZIKV envelope protein. These findings demonstrate that the surface chemistry of LDH influences the adsorption of antigens, their retention, and their further immune recognition, highlighting the importance of preserving antigen accessibility during the design of LDH-based nanovaccines.

Nanomaterials doi: 10.3390/nano16211418

Authors: Byeong Gwan Kim Jae Hyeon Jun Jun-Hyeok Choi Hyeon-Seok Shin Jung-Hun Jo Chan Bin Lee Jun Young Hong Jae Min Jo Byoung Hun Lee

The anti-ambipolar switch (AAS) produces a bell-shaped (Λ) transfer characteristic that embeds two threshold edges within a single device; however, this feature has been utilized mainly for discrete logic and periodic signals, rather than for discriminating a continuous input against defined voltage thresholds. Herein, a dual-gate ZnO–Te AAS (DGAAS), combined with a load transistor into an AAS cell, functions as an electrically programmable window detector. The bounded conduction interval of its Λ-curve defines the detection window, and the top-gate bias relocates this window without changes to the circuit topology. Fabricated at ≤150 °C, the device translates its peak by 0.95 V per volt of top-gate bias, with a device-to-device standard deviation of 29.4 mV across 30 devices. A six-transistor window detector, comprising the AAS cell and an output buffer, replaces the two-comparator-and-AND structure of a conventional CMOS design, reducing the transistor count by 75–77%, and circuit simulations based on the measured cell characteristics show that three cells map a continuous analog input to a 2-bit digital output. These results indicate that the ZnO–Te DGAAS serves as a compact primitive for voltage-domain signal discrimination, connecting analog sensing and digital readout within a back-end-of-line (BEOL)-compatible process.

Nanomaterials doi: 10.3390/nano16211417

Authors: Zimeng Cao Caixia Cheng Mengmeng Wang Yanjiao Liu Zhongpeng Wang Xiuju Wang Liguo Wang

Forward osmosis (FO) membranes have received growing attention in the field of water treatment. Nevertheless, their practical application in seawater desalination remains restricted, underscoring the imperative of developing advanced membrane modification techniques. In this study, we synthesized metal–organic framework MIL-53(Al) nanoparticles via a hydrothermal method and incorporated them into cellulose acetate (CA) membranes to fabricate a CA/MIL-53(Al) mixed-matrix FO membrane. The synthesized MIL-53(Al) nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption analysis. The effects of MIL-53(Al) loading, pore-forming agent content, mixing temperature, and coagulation bath temperature on the membrane performance were systematically investigated to optimize the fabrication conditions. Under the optimal conditions, the prepared CA/MIL-53(Al) mixed matrix FO membrane exhibited a water flux of 65.71 L/(m2·h) and a reverse salt flux of 2.20 g/(m2·h). Compared with the pristine CA FO membrane, the incorporation of MIL-53(Al) significantly improved the membrane permeability and separation performance. These enhancements were attributed to the improved hydrophilicity and optimized membrane structure induced by MIL-53(Al) nanoparticles. This study demonstrates that MIL-53(Al) is an effective nanofiller for the fabrication of high-performance CA-based FO membranes and provides a promising strategy for seawater desalination applications.

Nanomaterials doi: 10.3390/nano16211416

Authors: Anna Lizunova Dina Kostina Anna Shaikhtdinova Arina Sanatulina Ekaterina Kameneva Olesya Vershinina Konstantin Pilyushenko Elizaveta Marushko Ilya Tsaplin Egor Khramov Victor Ivanov

Poly-L-lysine (PLL) layers deposited by sequential spin coating as a multifunctional platform for plasmonic metal nanostructures were investigated. Using an identical deposition strategy, a cross-material comparison was performed for Pt, Al, and Ag nanoparticles and Ag nanowires. Increasing PLL thickness red-shifts the localized surface plasmon resonance (LSPR) by modifying the dielectric environment, and depends on nanoparticle size distribution, plasma frequency, and background dielectric contribution. Deposition of a 25 nm PLL layer results in absorption shifts of 63, 57, 28, and 45 nm for Al, Pt, and Ag nanoparticles and Ag nanowires, respectively. Mie theory simulations confirmed the experiments and revealed that larger particles exhibit stronger long-wavelength shifts. PLL-coated Al nanostructures preserved their optical response and photoluminescence-enhancing functionality after immersion in deionized water for up to 340 min. As a dielectric spacer, PLL controls the interaction between ZnO and Al nanoparticles and increased the ultraviolet (UV) photoluminescence enhancement factor of ZnO at 377 nm up to 2.1-fold relative to pure ZnO. The developed Al/PLL platform produced pronounced quenching of intrinsic IgG fluorescence at 330 nm. These findings established PLL coatings as a versatile unified strategy for precise spectral tuning of plasmonic resonances, controlling emitter/metal interactions, and stabilizing Al nanostructures for UV photonic and bioanalytical sensing.

Nanomaterials doi: 10.3390/nano16211415

Authors: Rossana Giaquinta Carmine Arnese Stefano Trocino

Tandem photoelectrochemical (PEC) cells made exclusively of earth-abundant oxides are a promising route to solar hydrogen, but bias-free operation and durability remain challenging, particularly in acidic environments. This work presents a 1 cm2 zero-gap tandem PEC cell, operated without housing and fed only with deionized water, that integrates an electrodeposited nanostructured WO3 photoanode (band gap 2.75 eV), a spray-coated nanostructured CuFe2O4 photocathode (1.43 eV) and a Nafion 117 proton-exchange membrane acting as solid electrolyte and separator. Mott–Schottky analysis in N2-purged 0.1 M HClO4 confirms the expected n-type and p-type semiconductor character, with a band-edge alignment compatible with unassisted operation. Under simulated AM 1.5G sunlight, the device delivers ≈42 µA cm−2 at zero bias (solar-to-hydrogen efficiency ≈ 0.05%, assuming unity Faradaic efficiency) and a saturated photocurrent density of 0.47 mA cm−2 at −1.0 V (throughput efficiency 0.70%). After 96 h of operation (48 h at 0 V and 48 h at −0.7 V), the photocurrent decreases by only ≈5–6%. Impedance spectroscopy and distribution of relaxation times analysis identify a dominant millisecond-scale interfacial charge-transfer process. Post-operando analyses reveal that WO3 undergoes only mild surface reduction, whereas CuFe2O4 shows partial Cu2+ → Cu+ reduction and local delamination, identifying the photocathode as the lifetime-limiting component.

Nanomaterials doi: 10.3390/nano16211414

Authors: Jinchun Guo Xinwei Zhou

Spatially uneven lithium (Li) growth in garnet solid electrolytes can accompany local mechanical damage. Here, operando scanning electron microscopy was used to follow Li growth on tantalum-doped lithium lanthanum zirconium oxide (LLZTO) under a localized tungsten-probe contact. Independent measurements on fractured and polished surfaces captured both contact-confined growth and visible extension beyond the initial contact region. On a polished surface, remote filamentary features elongated and branched over tens of micrometers. On a fractured surface, Li growth accompanied progressive opening and displacement of neighboring LLZTO regions. Site-specific scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy (EDX) examined a region after extended growth. The maps showed local Ta and Zr signal variations consistent with compositional nonuniformity. Cryogenic three-dimensional EDX revealed similar signal variations in a separate uncycled region. These elemental observations provide local material context for the growth sequences. Overall, the study documents distinct spatial growth modes and their temporal association with mechanical changes. Local composition is identified as a possible contributing factor alongside evolving contact and surface conditions.

Nanomaterials doi: 10.3390/nano16211413

Authors: Fengxia An Zihan Chen Binbin Wang Ke Zhuang Jiayun He Shunde Zou Xiaohuan Meng Enmin Zong Haopeng Luo Huan Chen Fang Jiang

Solar-driven interfacial evaporation offers a sustainable route to freshwater production, yet the role of evaporator microstructure in regulating water state and transport remains insufficiently understood. Here, chitosan-based photothermal aerogels with tunable lamellar architectures were fabricated by freeze-drying, using carbon nanotubes as broadband solar absorbers. Varying the chitosan concentration modulated the interlayer spacing and associated water state within the aerogels. The optimized CS2.5 aerogel exhibited the highest intermediate-water proportion and the lowest apparent evaporation enthalpy of 1652.1 kJ kg−1, while maintaining solar absorptance above 97.8%. Under 1 sun irradiation, CS2.5 achieved an evaporation rate of 2.33 kg m−2 h−1 and maintained stable performance in NaCl solutions of up to 15 wt%, organic-contaminated water, and prolonged cycling tests. Idealized COMSOL Multiphysics 6.3 simulations indicated that a moderate interlayer spacing promoted a uniform velocity distribution and smooth pressure gradient, thereby facilitating water transport. During six consecutive days of outdoor operation, the evaporator delivered daily evaporation yields of 1.38–2.30 kg m−2 under fluctuating environmental conditions. These findings provide insights into coordinating lamellar architecture, water-state regulation, and fluid transport for efficient solar evaporation.

Nanomaterials doi: 10.3390/nano16211412

Authors: Yihan Zhao Puyu Chen Antong Ren Zhuofan Wu Hao Zhou Xu Zhao Xiaojing Yang

The increasing demand for sustainable electrochemical energy-storage materials has stimulated considerable interest in biomass-derived porous carbons. In this study, hierarchical porous carbon was prepared from Suaeda salsa, a renewable halophytic biomass, through thermal pretreatment, carbonization, and KOH activation. The effects of thermal treatment and KOH activation on the pore structure, morphology, surface characteristics, and electrochemical behavior of the resulting carbons were systematically investigated. The results demonstrate that moderate KOH activation substantially opens the carbon framework and promotes the development of accessible porosity while retaining a finite meso/macro-pore network that can facilitate electrolyte transport. Among the investigated conditions, the intermediate activation level provided the most favorable balance between micropore generation, transport accessibility, and framework preservation, leading to the best electrochemical response. The combined structural and electrochemical analyses establish a clear processing–pore structure–property relationship and indicate that electrochemical performance cannot be optimized simply by increasing activation severity. Instead, rational control of hierarchical porosity is important for achieving effective charge storage and ion transport in biomass-derived carbon electrodes. The study provides a sustainable route for converting coastal halophytic biomass into functional porous carbon materials for electrochemical energy-storage applications.

Nanomaterials doi: 10.3390/nano16211411

Authors: Yifan Zhang Xin Yang Mingjun Huang Xin Guo Yujin Wang Zhifang Liu

Mining environments present complex respiratory hazards, including both respirable dust and toxic gases. Conventional protective materials typically address only one pollutant type, leaving a gap in integrated protection strategies. This review systematically examines the design of electrospun nanofibrous membranes for simultaneous dust filtration and gas removal. The discussion covers the fundamental mechanisms of particle capture and gas adsorption, the coupling effects between these two functions within a single membrane, and recent engineering strategies ranging from single-polymer systems to composite, hierarchical, and moisture-adaptive architectures. The integration of gas-removal functionalities is addressed through adsorptive materials, metal–organic frameworks for selective capture, photocatalytic degradation, and antimicrobial protection. The review concludes that integrated membrane design must move beyond single-function optimization toward balanced performance in particle capture, gas removal, airflow resistance, and environmental durability. Future progress depends on controlled spatial organization of functional components, humidity-resistant architectures, and standardized testing under realistic multicomponent exposure conditions.

Nanomaterials doi: 10.3390/nano16211410

Authors: Yilin Zhu Chaohua Tan

We investigate four-wave mixing (FWM) in a five-level atomic system coupled to an optical nanofiber. The transverse inhomogeneity of the guided field is incorporated through a mode-weighted mean-field approximation, yielding effective one-dimensional propagation equations. The conversion efficiency is evaluated over different detuning parameters and compared with a uniform-field reference under consistent normalization. For the parameters studied, the nanofiber model predicts higher peak conversion efficiencies, accompanied by distinct changes in the spectral response. The two-photon resonance narrows, the upper-transition resonance retains nearly the same bandwidth, and the range of probe detunings supporting appreciable conversion broadens. To account for the interplay among detuning parameters, particle swarm optimization (PSO) is employed, yielding a best-found efficiency of 1.85×10−3 within the prescribed search bounds. The resulting two-dimensional efficiency map exhibits a tilted high-efficiency band, revealing a correlated dependence on the detunings rather than independently optimized resonances. These findings clarify how transverse mode confinement and coupled detuning conditions shape the spectral response of FWM in the nanofiber–atom system.

Nanomaterials doi: 10.3390/nano16211409

Authors: Xiangzhi Cui

The global transition toward carbon neutrality and sustainable energy systems has placed electrocatalysis at the center of modern energy research [...]

Nanomaterials doi: 10.3390/nano16211408

Authors: Fengyu Li Jingxiang Zhao

Low-dimensional nanomaterials, including zero-dimensional (0D) nanoclusters, one-dimensional (1D) nanoribbons and nanotubes, and two-dimensional (2D) nanosheets, exhibit distinctive physical and chemical properties with potential applications in nanoelectronics, quantum technologies, catalysis, and energy conversion [...]

Nanomaterials doi: 10.3390/nano16211407

Authors: Claudia Barbagallo Francesca Lo Presti Anna Lucia Pellegrino Luca Pulvirenti Martina Lippi Patrizia Rossi Graziella Malandrino

Cesium-based fluoride thin films are attracting growing interest in photovoltaic and optoelectronic applications due to their optical properties, which make them suitable as hosts for lanthanide-based energy conversion layers. Here, we report a one-pot synthesis of a novel heterobimetallic single-source adduct with formula [Cs(tetraglyme)2]+[Y(hfa)4]− (hfa = hexafluoroacetylacetonate; tetraglyme = 2,5,8,11,14-pentaoxapentadecane). The compound has been fully characterized by FT-IR spectroscopy, energy-dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). A partial structure of Cs-Y has been obtained by single-crystal X-ray diffraction, thus confirming the ionic nature of the Cs-Y complex and a well-defined coordination environment for both metal centers. Using a sol–gel/spin-coating approach, the complex has been used as a single-source precursor for the fabrication of pure CsY2F7 phase as thin films on silicon and quartz substrates. The films exhibit homogeneous morphology and stoichiometry, making CsY2F7 a promising host material for energy conversion layers for application in solar cells. As a proof-of-concept, a luminescent Eu-doped CsY2F7 film has been fabricated. This study represents the first work on the deposition of Cs-Y fluoride layers.

Nanomaterials doi: 10.3390/nano16211406

Authors: Sidhaling B. Bhairunagi Ketankumar A. Ganure Neha Kondal Rekha M. Ovhal Vishwajeet V. Aherkar Laxman A. Dhale R. Saidur Sharanabasava V. Ganachari

Cadmium sulphide (CdS) semiconductor nanocrystals are of interest because of their optical properties and potential in photocatalysis. Here, we examine their structural, optical, photocatalytic, electrochemical, antimicrobial, and theoretical characteristics for possible environmental and energy-related applications. CdS nanocrystals were prepared by aqueous co-precipitation. X-ray diffraction (XRD) confirmed the formation of hexagonal wurtzite CdS, while FESEM, HRTEM, and EDAX were used to examine morphology, crystallinity, and elemental composition. UV–visible spectroscopy and Tauc analysis gave an optical band gap of 2.15 eV. Under visible-light irradiation, the material degraded 89.93% of methylene blue within 120 min. Antibacterial activity was also observed against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Pseudomonas aeruginosa. Cyclic voltammetry yielded a specific capacitance of 17.75 F g−1, indicating the potential of the material for further investigation in energy storage applications. Density functional theory (DFT) calculations were used to examine the electronic structure, charge distribution, and related features of the CdS nanoclusters. Taken together, the experimental and theoretical results provide an initial assessment of the multifunctional behaviour of the prepared CdS nanocrystals. Further work is needed to establish their performance and safety under application-specific conditions.

Nanomaterials doi: 10.3390/nano16211404

Authors: Seokhyun Ko Muhammad Ali Jin Hyun Kim Honghyun Cho Jeonggyun Ham

This study experimentally investigated CO2 absorption in APTES-modified Fe3O4/water nanofluids under continuous bubbling at nanoparticle concentrations of 0–0.1 wt% and temperatures of 10, 20, and 30 °C. Performance was evaluated using effective CO2 uptake and the apparent absorption rate constant, with enhancements calculated relative to deionized (DI) water at the same temperature. Effective uptake decreased with increasing temperature and exhibited a nonmonotonic concentration dependence, whereas normalized uptake profiles generally indicated a more rapid approach to the final uptake at higher temperatures. The highest uptake was 2.084 g L−1 at 10 °C and 0.01 wt%. The largest uptake enhancement was approximately 13.2% at 30 °C and 0.05 wt%, although the apparent rate constant decreased by approximately 4.1% under this condition. The greatest kinetic enhancement occurred at 10 °C and 0.1 wt%. Enhancement ranges across concentrations widened with increasing temperature for both metrics, while the largest ranges across temperatures occurred at different concentrations for uptake and kinetics. Normalized performance maps showed that conditions favoring uptake did not necessarily maximize the kinetic benefit of nanoparticle addition. These results support selecting nanoparticle concentration in relation to operating temperature and the relative importance of uptake and absorption rate.

Nanomaterials doi: 10.3390/nano16211405

Authors: Huijuan Dong Yongmei Xue Jianwei Liu Zhihong Liu Zejun Wang

Substrate orientation offers a route to tailoring the dielectric and energy-storage properties of lead-free oxide thin films. In this work, 1.0 mol.% Mn-doped 0.96NaNbO3–0.04CaZrO3 (NNCZ–Mn) thin films were fabricated via a sol–gel method on (100)-, (110)-, and (111)-oriented Nb-doped SrTiO3 substrates and exhibited corresponding preferential out-of-plane orientations. The (111) film combined higher permittivity and lower leakage current with a larger recoverable polarization, yielding the best energy-storage performance among the three orientations. It achieved a recoverable energy density of approximately 23 J/cm3 with an efficiency of 65% at an electric field of 666.67 kV/cm and reached approximately 35 J/cm3 at 970 kV/cm with an efficiency of 48%. Its recoverable energy density also exhibited moderate thermal stability over 23–160 °C, good frequency stability over 400–2000 Hz, and good fatigue resistance after 106 cycles. This study demonstrates the potential of substrate orientation control for improving solution-processed NaNbO3-based thin-film capacitors.

Nanomaterials doi: 10.3390/nano16211403

Authors: Yajun Tian Lingsen Meng Qijin Cheng

Heteroepitaxial growth of β-Ga2O3 thin films on Si for solar-blind ultraviolet photodetectors faces severe challenges due to lattice mismatch and interfacial oxidation, leading to high dark current and low responsivity. In this work, β-Ga2O3 thin films were deposited on n-Si(100), p-Si(100), and p-Si(100) substrates with a 100 nm thermally oxidized SiO2 buffer layer using plasma-enhanced chemical vapor deposition. Metal-semiconductor-metal structured solar-blind ultraviolet photodetectors were subsequently fabricated. The effects of the SiO2 buffer layer on the crystalline quality, interfacial characteristics, and optoelectronic performance of the devices were systematically investigated. Results show that the SiO2 buffer layer possibly relieves the mismatch-induced stress in Ga2O3 films on Si, suppresses the formation of an uncontrollable interfacial layer tentatively assigned as SiOx-like (x ≤ 2) during the initial deposition stage, and significantly improves the crystalline quality of β-Ga2O3 films. Compared with devices on bare Si substrates, the photodetector based on the SiO2-buffered substrate exhibits a significantly reduced dark current, a photo-to-dark current ratio of 5.01 × 103, a responsivity of 3.32 A/W, a theoretical shot-noise-limited specific detectivity of 1.14 × 1013 Jones, and a UV-to-visible rejection ratio as high as 8.12 × 105 at 5 V. The overall performance of the SiO2-buffered device is markedly superior to that of bare Si devices, albeit with a slight decrease in response speed. Mechanism analysis reveals that the dense SiO2 buffer layer blocks the vertical leakage path of carriers toward the Si substrate, simultaneously relieving the mismatch-induced stress and improving film quality. This work provides a feasible technical pathway toward low-cost, CMOS-compatible high-performance silicon-based solar-blind ultraviolet photodetectors.

Nanomaterials doi: 10.3390/nano16211402

Authors: Jiayu Di Shuixiu Lyu Liuyi Li Dawei Wang Bin Lu

The rapid development of optoelectronic technologies has placed ever-increasing demands on high-performance photodetectors, as the intrinsic properties of the active materials fundamentally determine the detection limit and operational stability. Although organic–inorganic hybrid perovskites exhibit superior optoelectronic properties, lead-based perovskites suffer from the drawbacks of heavy-metal toxicity and poor structural stability, which severely limit their practical applications. Low-dimensional lead-free perovskite single crystals have therefore emerged as a promising material system, owing to their extremely low defect density, grain-boundary-free nature, and strong intrinsic stability. Here, high-quality 0D lead-free MA3Sb2I9 single crystals were grown via a seed-induced two-step crystallization method, and photodetectors based on these single crystals were fabricated. The resulting photodetector exhibits a high responsivity of 22.77 A/W, an external quantum efficiency (EQE) of 6971.92%, and a specific detectivity of 1.49 × 1012 Jones. Notably, stable photoresponse was maintained over ~450 on/off switching cycles, evidencing excellent operational repeatability and long-term stability. These results highlight the great potential of MA3Sb2I9 single crystals as a stable, lead-free candidates for high-performance photodetection.

Nanomaterials doi: 10.3390/nano16211401

Authors: Liping Cai Jie Huang Guilin Chen

Tin sulfide (SnS) has emerged as a highly promising absorber material for thin-film solar cells owing to its excellent optoelectronic characteristics and earth-abundant composition properties. However, it is worth noting that the power conversion efficiency (PCE) of SnS-based thin-film solar cells (TFSCs) is still far below their theoretical potential of approximately 32.0%, and the factors leading to poor performance mainly include high recombination rate, short minority carrier lifetime, and unfavorable conduction band offset (CBO) at pn junction interface. In this study, we selected CdS, ZnSe, and ZnS:In as electron transport layers, NiOx, PEDOT: PSS, Spiro-OMeTAD, CuI, and CuSCN as hole transport layers, and compared them through SCAPS-1D simulation to optimize device performance. In addition, the impacts of the SnS absorber layer thickness and doping concentration, bulk defect density, electron transport layer, hole transport layer, and electrode work function on the device performance have been systematically studied using SCAPS-1D. The results show that the solar cell with Al/ITO/ZnS:In/SnS/NiOx/Au/SLG architecture can achieve a maximum PCE of 27.01%. This simulation aims to explore the theoretical performance ceiling of SnS-based architecture rather than predicting experimentally realizable efficiency. This study provides theoretical guidance for the design of high-performance, low-cost SnS-based thin-film solar cells.

Nanomaterials doi: 10.3390/nano16211400

Authors: Quoc Hai Nguyen Shalini Sahani Phan Khanh Thinh Nguyen

CO2 conversion has emerged as a sustainable and environmentally friendly strategy for producing value-added fuels and chemicals while mitigating greenhouse gas emissions. However, the practical implementation of conventional CO2 conversion technologies is often hindered by sluggish reaction kinetics, unfavorable thermodynamics, and complex multistep reaction pathways. Since their first discovery in 2011, MXenes have attracted significant attention as promising catalytic materials owing to their unique physicochemical properties, including high electrical conductivity, tunable surface chemistry, large specific surface area, and excellent charge-transfer capability. Consequently, MXene-based photocatalysts have demonstrated remarkable progress in solar-driven CO2 conversion applications. This mini-review provides a basic overview of recent advances in MXene-based composites for CO2 conversion. First, the fundamental characteristics of MXenes, including their synthesis strategies and key physicochemical properties relevant to photocatalytic CO2 conversion, are introduced. Subsequently, recent developments in MXene-based photocatalytic systems for CO2 reduction are basically discussed. Finally, the current challenges, future opportunities, and research directions for engineering high-performance MXene-based composites are highlighted. This review aims to provide both newcomers and experienced researchers with a concise understanding of MXene materials and their growing potential in photocatalytic CO2 conversion.

Nanomaterials doi: 10.3390/nano16211399

Authors: Mohamed Saleh M. Esmail Yassine Bouazzi Mabrouk Touahmia Zied Elleuch Sayed El. Soliman

High-resolution optical thermal sensors are attracting increasing interest due to their potential for compact integration, electromagnetic immunity, and enhanced spectral precision. In this work, a topological mirror heterostructure based on a one-dimensional photonic crystal (1DPC) is proposed for thermal sensing applications. The structure incorporates alternating silicon/glycerin photonic layers with a glycerin defect cavity, combining the large thermo-optic response of glycerin with the strong field localization of topological edge states in a topological mirror configuration. Finite element method (FEM) simulations reveal the formation of ultranarrow resonant modes with near-unity transmission inside the photonic bandgap. The proposed topological mirror heterostructure achieves exceptional thermal sensing performance through ultranarrow resonant linewidths and strong optical confinement, resulting in ultrahigh quality factors and figures of merit. The optimized design exhibits a thermal sensitivity of −0.1177 nm/°C, a quality factor approaching 1.8 × 108, and a figure of merit of 1.53 × 104 °C−1. The proposed platform offers a promising approach to compact photonic thermal sensors that require high spectral resolution and enhanced sensing efficiency.

Nanomaterials doi: 10.3390/nano16211398

Authors: Nataliya A. Sakharova André F. G. Pereira Jorge M. Antunes

Group 13–phosphide nanosheets and nanotubes represent a family of nanostructures whose mechanical properties remain unevenly explored, particularly across the complete B–Al–Ga–In–Tl series. In this work, the elastic behavior of boron phosphide, aluminum phosphide, gallium phosphide, indium phosphide and thallium phosphide nanosheets and single-walled nanotubes is systematically investigated using nanoscale continuum modeling based on molecular structural mechanics and finite element analysis. The surface Young’s and shear moduli of the nanosheets are evaluated and their variation along the group 13–phosphide series is analyzed. The corresponding nanotubes are investigated considering zigzag, armchair and chiral configurations with diameters above 1.3 nm to assess the influence of geometry and chirality on their elastic response. The results reveal an overall decrease in the elastic properties along the B–Al–Ga–In–Tl series, although the trend is not uniform for all compounds and properties. The surface Young’s moduli of the nanotubes are found to be comparable to those of the corresponding nanosheets, whereas their surface shear moduli are consistently higher, despite the different deformation modes involved. Overall, this study provides a consistent assessment of the mechanical behavior of both 2D and 1D group 13–phosphide nanostructures within a unified modeling framework, while also providing reference data for compounds whose elastic properties remain scarcely reported.

Nanomaterials doi: 10.3390/nano16211397

Authors: Yanzhu Ye Zhongshui Li Alian Wang Shen Lin

In photocatalyst design, constructing p–n heterojunctions is a highly effective way to suppress photogenerated charge recombination and enhance photocatalytic activity. In this study, a precious-metal-free Co3O4/Zn0.4Cd0.6S p–n heterojunction composite was prepared using a facile solvothermal approach. The photocatalytic activity and long-term stability are significantly promoted by the introduction of Co3O4. The composite containing 4 wt% Co3O4 demonstrates a maximum H2 generation yield of 56.63 mmol g−1 h−1, which represents a 6.8-fold improvement over pristine Zn0.4Cd0.6S, significantly surpassing many comparable photocatalysts and even exceeding that of some noble-metal-modified composites. The apparent quantum efficiency (AQE) of 4 wt%-Co3O4/Zn0.4Cd0.6S reaches up to 21.86% at 420 nm. Systematic characterization reveals that the photocatalysts’ p–n heterojunction underlies the remarkable improvement in activity and durability of the composite through facilitated separation and migration of photoinduced electrons and holes. The p–n heterojunction-driven charge separation enhancement fundamentally underpins this significant performance leap. These findings demonstrate a promising approach for developing cost-effective, high-activity photocatalysts for sustainable energy applications.

Nanomaterials doi: 10.3390/nano16211396

Authors: Brenda Arriaga-García Reyna Isabel Rojas-Martínez Ana María Hernández-Anguiano Víctor Manuel Zúñiga-Mayo Julio Huerta Espino

Copper oxide nanoparticles (CuO NPs) have attracted increasing interest in agriculture due to their antimicrobial properties and potential for sustainable plant disease management. In this study, CuO NPs were synthesized via chemical precipitation, and their antifungal activity and morphological impacts were evaluated against the phytopathogen Fusarium graminearum and the biocontrol agent Trichoderma harzianum. Comprehensive physicochemical characterization confirmed the formation of highly pure, quasi-spherical CuO NPs with an average size of 10.9 ± 0.7 nm as determined by TEM. Furthermore, Raman spectroscopy and X-ray diffraction (XRD) revealed a highly crystalline monoclinic tenorite phase (space group C2/c) with an average crystallite size of 9.6 ± 0.7 nm, confirming the single-crystal nature of the nanomaterial. The CuO NPs exhibited marked antifungal activity against F. graminearum, achieving 100% growth inhibition at 500 ppm, accompanied by severe hyphal deformation and cell wall collapse. In contrast, T. harzianum showed tolerance, maintaining growth up to 800 ppm. SEM analysis revealed that under sublethal stress, both fungi differentiated vegetative mycelium into chlamydospores as a survival strategy. Furthermore, a low concentration (50 ppm) of CuO NPs stimulated T. harzianum sporulation by 30.4% relative to the control, consistent with a hormetic-type response. These findings highlight a differential sensitivity of the two fungi to CuO NPs in vitro. While the nanoparticles effectively inhibit the phytopathogen, the beneficial biocontrol fungus exhibits remarkable tolerance. Although these results provide a promising basis for exploring the combined use of CuO NPs and T. harzianum-based biofungicides, further in vivo studies evaluating this interaction with the plant are necessary to confirm their compatibility and efficacy in sustainable integrated disease management.

Nanomaterials doi: 10.3390/nano16211395

Authors: Zhiqiang Zeng Mingshu Zheng Lin Yang Rui Xu

Vertically ordered nanopillar (NP) arrays with sharp nanoedges are attractive for electrocatalytic hydrogen evolution reaction (HER) because the vertically ordered architecture provides efficient transport pathways and large accessible surface areas, while the sharp nanoedges enhance local electric fields and current densities. However, the fabrication of such vertically ordered nanostructures with sharp nanoedges remains challenging. Here, we report an anodic aluminum oxide (AAO) template-assisted strategy to construct vertically ordered triangular Pt/Ni NP arrays with sharp nanoedges for enhanced HER activity. To demonstrate the advantages of triangular NPs, circular Pt/Ni NPs with similar dimensions, composition, Pt chemical states and crystalline phases, and core–shell structures were also fabricated by the same AAO template-assisted strategy as a control to investigate the geometric effect. Electrochemical measurements demonstrate that the triangular NPs exhibit 35% higher HER activity at −100 mV vs. RHE compared to their circular counterparts. Furthermore, COMSOL (Multiphysics 5.5) simulations reveal that the sharp nanoedges induce locally enhanced electric fields and current densities, providing critical insight into the geometry-dependent electrochemical enhancement. This work demonstrates that our AAO template-assisted strategy can construct vertically ordered nanostructures with sharp nanoedges, and that these vertically ordered sharp nanoedges can enhance HER catalytic activity.

Nanomaterials doi: 10.3390/nano16211394

Authors: Jonathan Suazo-Hernández Paula Maldonado Erick Zagal María de Los Ángeles Sepúlveda-Parada Antonieta Ruiz Cristian Urdiales Collin G. Joseph Lizethly Cáceres-Jensen Patricia Poblete-Grant

Excessive release of engineered nanoparticles (NPs) into the environment can affect the biological and chemical properties of soils. This study evaluated the effects of two commercial metallic copper nanoparticles (Cu-NPs 25 nm; CuNPs/25, and Cu-NPs 40–60 nm; CuNPs/40–60) on enzymatic activity and nutrient bioavailability in an agricultural soil. An incubation experiment was conducted using Ultisol soil treated with 500 mg kg−1 CuNPs/25 or CuNPs/40–60, simulating a high-exposure scenario, in the presence and absence of 200 mg kg−1 P (K2HPO4). Acid phosphatase, alkaline phosphatase, and β-glucosidase enzymatic activities along with P bioavailability were measured at 0.14, 1, 3, 5, and 8 weeks. The results showed that in most instances, 500 mg kg−1 CuNPs/25 or CuNPs/40–60 significantly decreased the activities of acid phosphatase, alkaline phosphatase, and β-glucosidase. The P bioavailability in soil was lower in the presence of CuNPs/25 than Cu-NPs/40–60. In addition, the Cu2+ concentrations in the water-extractable fraction were higher than in the CaCl2 fraction, and the increase in water-extractable Cu2+ concentrations in the soil solution was correlated with a decrease in enzyme activities. Eight weeks of exposure to NPs did not cause any marked changes in organic matter content or electrical conductivity. However, the Cu2+-(DTPA) bioavailability in soil treated with 500 mg kg−1 CuNPs/25 and CuNPs/40–60 for 8 weeks increased over 90 times, regardless of the presence or absence of P. However, these findings should be interpreted in the context of a high-exposure scenario for CuNPs and should not be directly extrapolated to environmentally realistic exposure levels.

Nanomaterials doi: 10.3390/nano16211393

Authors: Yixuan Hu Jun Ke Zhaoyang Yan Jie Liu

In this work, a novel ZnO@C/Bi/Bi2MoO6 heterojunction is synthesized by assembling bismuth molybdate (Bi2MoO6) and ZIF-8-derived ZnO@C through a hydrothermal method for enhancing the photo-Fenton-like performance, where a tight interface contact is efficiently formed. The heterojunction not only improves the harvesting ability to visible light, but also promotes the separation and transfer of photogenerated electrons and holes. As a result, BZ400-2 achieves 69.8% degradation of tetracycline (TC) within 90 min under visible light irradiation (300 W Xe lamp; λ > 420 nm), with an apparent pseudo-first-order rate constant of 0.01081 min−1. Meanwhile, radical quenching experiments and ESR measurements confirm the involvement of·O2−, 1O2 and ·OH in the reaction system. Furthermore, the results of DFT theory demonstrate that the phenolic hydroxyl, ketone, and dimethylamine groups of tetracycline hydrochloride are more susceptible to free radical attack. Furthermore, the QSAR-based toxicity predictions suggest that most of the identified degradation intermediates exhibit lower acute toxicity than TC.

Nanomaterials doi: 10.3390/nano16211392

Authors: Alvin Kambondo Jie Wang Huang Pan

The influence of boron surface contamination on oxygen activation and subsequent hydrogen adsorption on Ti-V-Nb non-evaporable getter (NEG) surfaces was investigated using density functional theory (DFT). A series of boron concentrations from 0 to 66.7 at.% was systematically introduced into the surface layer, spanning dilute perturbation to strong surface reconstruction regimes. Chemisorbed oxygen was fixed in a consistent configuration to simulate the passivating oxide overlayer formed under realistic conditions. Two independent performance criteria were considered. These were ease of activation, assessed by oxygen vacancy formation energy, and hydrogen pumping capability, assessed by H2 adsorption energy. The results reveal that moderate boron contamination at 41.7 at.% reduces the average oxygen vacancy formation energy by 1.232 eV, promoting easier oxygen removal, while excessive boron loading leads to oxygen trapping. Screening the concentrations by this descriptor therefore identifies 5B as the least detrimental to activation within the investigated range. On this surface, H2 adsorption is strongly site-dependent, with bridge and hollow sites exhibiting dissociative chemisorption. PDOS analysis shows that B 2p states mediate hydrogen activation either directly through B 2p-H 1s hybridization at the hollow site or indirectly by modifying the neighbouring metal centres at the bridge site, while the elevated work function of the 5B surface reflects enhanced surface dipole strength rather than a barrier to H2 adsorption. LST/QST calculations reveal a forward barrier of 0.422 eV for hydrogen migration from the surface into the subsurface, with the subsurface state thermodynamically more stable by 0.531 eV. These findings establish that moderate boron contamination does not severely hinder oxygen removal or eliminate hydrogen uptake, providing atomic-scale insight for fusion-relevant environments where boronization is routinely applied as a wall conditioning technique to suppress plasma contamination and sustain high-quality plasma confinement.

Nanomaterials doi: 10.3390/nano16211391

Authors: Lívia Mačák Jana Ondrašovičová Martina Zigova Marek Vojtko Maksym Lisnichuk Silvia Ondrašovičová Peter Pal’ove-Balang Ján Király

Silver nanoparticles (AgNPs) synthesized using plant extracts represent a promising approach combining environmentally friendly nanoparticle synthesis with potential biomedical applications. In this study, AgNPs were synthesized using aqueous extracts of dried Lavandula angustifolia (LEx) and Salvia rosmarinus (REx) leaves, physicochemically characterized, and evaluated for their antiproliferative activity against six human cancer cell lines and one non-tumorigenic human cell line. HPLC analysis revealed distinct phytochemical profiles of the two extracts, while UV–Vis, FTIR, TEM, SAED, and SEM–EDX analyses were used to characterize the resulting lavender-mediated (LAg) and rosemary-mediated (RAg) AgNPs. TEM analysis showed a greater proportion of smaller nanoparticles in RAg than in LAg. Antiproliferative activity was evaluated using the MTT assay after 48 h of exposure, with LEx, REx, and AgNO3 included as controls. Both AgNP formulations exhibited cell-line-dependent activity. LAg reached IC50 values of 19.4–20.8 µmol Ag/L in five cancer cell lines, whereas RAg reached IC50 values of 14.4–25.2 µmol Ag/L. The lowest IC50 was observed for RAg in PaTu 8902 pancreatic adenocarcinoma cells (14.4 ± 0.6 µmol Ag/L). In contrast, the IC50 was not reached in A549 or non-tumorigenic CCD-18Co cells at concentrations up to 50 µmol Ag/L (IC50 > 50 µmol Ag/L). Neither LEx nor REx produced 50% inhibition of cell viability at concentrations up to 1.7% (v/v). Similarly, AgNO3 did not achieve 50% inhibition at concentrations up to 50 µmol/L in any of the cell lines tested. These findings demonstrate formulation- and cell-line-dependent antiproliferative activity of green-synthesized AgNPs and support further investigation of their biological effects and underlying mechanisms.

Nanomaterials doi: 10.3390/nano16211390

Authors: Izabela Constantinoiu Cristian Viespe Cornelia Enache

This study investigates ZnO-based surface acoustic wave (SAW) sensors for the detection of methane (CH4) at room temperature (RT), focusing on the influence of film morphology and oxide heterostructures developed by pulsed laser deposition (PLD). Bilayer thin films—specifically ZnO/CuO and ZnO/In2O3—were deposited onto quartz substrates at 400 °C under oxygen pressures of 100 and 700 mTorr to evaluate how deposition conditions affect sensor performance. Structural and morphological characterization was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). ZnO thin films deposited at 700 mTorr exhibited a more open, granular morphology compared to those deposited at 100 mTorr, a feature likely to facilitate gas access to the sensor’s active surface. The addition of CuO and In2O3 top layers further influenced the sensor response, presumably through surface and interface effects. Among the configurations studied, sensor S6 (ZnO/CuO, with both layers deposited at 700 mTorr) demonstrated the highest sensitivity—0.18 Hz/ppm—within the experimentally investigated CH4 concentration range (0.4–2%), with an estimated limit of detection (LOD) of 167 ppm. Short-term measurements performed on sensors S4 and S6 at a 2% CH4 concentration indicated reversible responses over two consecutive exposure and recovery cycles, with a return to the initial baseline value following the removal of the gas. These results suggest that ZnO-based double layers, fabricated via PLD, are promising candidates for further investigation as CH4-sensitive layers at RT.

Nanomaterials doi: 10.3390/nano16211389

Authors: Rakshya Panta Howyn Tang Lina Elrofaie Jin Zhang

Black phosphorus nanosheets (BPNS) are emerging two-dimensional (2D) materials with exceptional optical and electronic properties, making them promising candidates for a wide range of nanotechnology applications. Their distinctive structural, electronic, and optical characteristics, particularly their thickness-dependent direct band gap, which varies from approximately 0.3 eV in bulk black phosphorus to 2.0 eV in the monolayer, have been extensively investigated using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations. This review focuses on the anisotropic optical responses of BPNS, including their polarization-dependent linear absorption and reflection, as well as nonlinear optical phenomena such as saturable absorption and the Kerr effect. In addition, the potential applications of BPNS in solar cells, sensors, and biomedical devices are discussed, with particular emphasis on their tunable band gap and enhanced sensitivity. Their reported biodegradability and generally favorable biocompatibility in preclinical studies further support their potential in nanomedicine, although these properties depend on formulation, dose, and surface modification. Despite these promising properties, challenges related to large-scale synthesis and environmental stability remain. Addressing these limitations through scalable synthesis approaches and improved stability will be essential for translating the unique capabilities of BPNS into practical applications.

Nanomaterials doi: 10.3390/nano16211388

Authors: Didi Song Wei Li Lijia Wan Yufang Liu Xiaohu Wu Kun Yu

Accessing mid-infrared narrowband absorption is crucial for applications such as spectroscopic analysis, infrared imaging and optical sensing. Here, we investigate the interaction between light and α-phase molybdenum trioxide (α-MoO3) nanocavities, uncovering pronounced and highly tunable resonant responses across the hyperbolic transition regime. Moving beyond standard phonon polariton excitations, our results reveal that the elevated refractive index of α-MoO3 beyond the Reststrahlen band promotes strong electromagnetic confinement and enhanced light-matter coupling in subwavelength nanostructures across the 12–13 μm spectral window. Analysis of the electric-field distributions reveals a hybrid collective mode arising from the interaction between Fabry–Perot cavity modes and geometry-dependent Mie-type resonances, leading to absorption approaching unity together with spectrally sharp resonances exhibiting quality factors exceeding 100 near the transverse-optical phonon frequency of α-MoO3. These findings provide novel insights for the development of compact mid-infrared photonic structures for tailoring thermal emission and enhancing electromagnetic coupling in α-MoO3-based nanophotonic platforms.

Nanomaterials doi: 10.3390/nano16211387

Authors: Fatehia S. Alhakami Ashjan M. Alharbi Aliaa Alrashidi Mohammed S. Alotaibi Ehssan Moglad Nourah A. Albarrak Afnan A. Alamri Emre Cevik Amani M. Alansi Talal F. Qahtan

Sunlight-assisted plant-mediated synthesis of silver nanoparticles (AgNPs) is well established, yet the complementary use of fluorescence spectroscopy to examine the optical response of complex phytochemical-containing media remains of interest. Here, Cucurbita pepo peel extract (CPE) was used for rapid AgNP formation under natural sunlight using single-step (A-Sun) and dropwise (B-Sun) addition strategies. The characteristic localized surface plasmon resonance (LSPR) band developed near 445–450 nm within 5 min, while corresponding dark controls showed negligible nanoparticle formation over the same period. Both dispersions retained their characteristic LSPR response during six months of optical monitoring. Steady-state photoluminescence (PL) measurements at excitation wavelengths of 300–350 nm and excitation–emission matrix (EEM) fluorescence mapping revealed lower recorded fluorescence intensities in the order CPE > A-Sun > B-Sun, with the principal emission region remaining broadly preserved near 435–440 nm. These observations provide complementary fluorescence fingerprints of the investigated preparations; however, inner-filter effects and light scattering may contribute to the measured attenuation, preventing its exclusive assignment to molecular quenching. FTIR revealed changes in oxygen-containing functional-group vibrations, while TEM showed predominantly spherical to quasi-spherical AgNPs, with mean particle diameters of 11.88 ± 3.60 nm for A-Sun and 9.77 ± 3.43 nm for B-Sun. The resulting dispersions also exhibited antibacterial activity against the six investigated bacterial strains. Overall, integrating PL and EEM with conventional characterization provides additional information on fluorescence changes accompanying sunlight-assisted AgNP formation without directly establishing the individual phytochemical reducing species, electron-transfer steps, or molecular surface-capping mechanisms.

Nanomaterials doi: 10.3390/nano16211386

Authors: Nguyen Thi Huyen Nguyen Quynh Chi Nguyen Thu Loan Simon Chouteau Jarl Tynan Collado Pierre Vinchon Vu Ngoc Linh Man Minh Tan Nguyen Hoang Tung Nguyen Thanh Tung Nguyen Nhat Linh

Gold nanoparticles (AuNPs) are attractive substrates for surface-enhanced Raman scattering (SERS) because of their strong visible plasmon resonance, chemical stability, and biocompatibility. However, the enhancement they provide depends on how accessible the gold surface is to the analyte. Tannic acid (TA) is an effective green reductant and stabilizer for AuNPs. Conventional TA-based syntheses, however, require large doses and boiling, leaving a dense organic shell on the particles. Herein, an argon cold atmospheric-pressure plasma jet combined with a low dose of TA reduced HAuCl4 to AuNPs at room temperature without additional chemical reductants. Well-dispersed colloids of quasi-spherical, crystalline particles about 10 nm in size formed with 25-fold less TA than was required without plasma. In situ UV–Vis spectroscopy showed that low-dose TA largely removed the induction period of plasma reduction and that particle growth continued after the discharge was switched off. This result suggests that plasma supplies most of the reducing power, whereas TA stabilizes the nascent nuclei. XPS confirmed metallic gold, with a small positive Au 4f shift consistent with surface-bound TA. The lightly capped AuNPs gave stronger methylene blue SERS signals than both TA-free plasma AuNPs and AuNPs prepared with 25-fold more TA. This room-temperature route therefore provides clean colloidal AuNPs as promising SERS substrates for chemical sensing.

Nanomaterials doi: 10.3390/nano16211385

Authors: Giorgos S. Avntoulla Georgios I. Giannopoulos

Two-dimensional covalent C60 networks are molecularly derived carbon allotropes in which intact fullerene cages form the repeating units of an extended lattice. Since isolation of a monolayer network in 2022, the field has expanded from synthesis to fracture, transport, excitonics, tribology, membranes, catalysis and energy storage. Growth has outpaced comparability: nominally identical quantities can refer to different structures, methods or dimensional conventions. Using literature verified through to 9 September 2026, we review the field within an evidence-graded framework and restate recoverable mechanical results on a thickness-independent basis. For the quasi-hexagonal phase, moduli published in GPa span 49.6–218.5 GPa (~4.4-fold), whereas the recoverable/native set occupies 93–189 N m−1 (~2.0-fold). Because the populations are not identical, this is a benchmarking diagnostic rather than an effect size; the narrower recoverable range is consistent with thickness conventions contributing to the apparent scatter. Thermal transport remains less settled: the direct experimental benchmark (~2.7 W m−1 K−1) is for micrometre-thick layered material, while monolayer simulations span a few to >100 W m−1 K−1. Electronic studies establish a semiconducting, anisotropic platform, although reported gaps remain observable- and method-dependent. We conclude with reporting standards and research priorities for comparable C60-network studies.

Nanomaterials doi: 10.3390/nano16211384

Authors: Canbo Hu Xinyue Gao Guoqin Cao Fanfan Liu

Mg–air batteries have garnered substantial research attention owing to their high specific capacity, low electrode potential, environmental benignity, and abundant natural magnesium reserves. Nevertheless, sluggish oxygen reduction reaction (ORR) kinetics at the air cathode severely restrict their practical implementation, which necessitates the development of low-cost, high-activity non-precious metal electrocatalysts. Herein, modified Mo2C@P electrocatalysts are successfully synthesized via phosphidation of Mo2C mixed with sodium hypophosphite (NaH2PO2) under thermal treatment. Multiple characterization techniques are employed to systematically investigate the crystal structure, chemical bonding configuration, micromorphology, and ORR electrocatalytic performance of the as-prepared materials. Meanwhile, Mg–air battery evaluations are carried out in 3.5 wt.% aqueous NaCl electrolyte. The results reveal that the Mo2C MXene backbone is well retained. Phosphorus doping is confined to surface modification and is accompanied by the formation of P–O and P–C bonds. The stacked lamellar architecture undergoes surface reconstruction, generating a uniform particulate morphology. The ORR electrocatalytic activity exhibits a volcano-type trend with phosphidation temperature, and Mo2C@P-350 achieves the highest limiting diffusion current density of 2.87 mA cm−2. The Mg–air battery assembled with Mo2C@P-350 delivers outstanding and stable discharge voltages of 1.19 V at 5 mA cm−2 and 1.13 V at 10 mA cm−2, along with optimal rate capability. This work demonstrates that mild-temperature phosphidation represents a reliable surface-engineering strategy for constructing high-performance ORR electrocatalysts.

Nanomaterials doi: 10.3390/nano16211383

Authors: Gilberto Nardi Sofia Zinzani Leonardo Stefanelli Francesca Baletto

As modelling the synthesis of metallic nanoparticles leads to useful insights that guide experiments, we propose a novel numerical suite, NPGrowth, which is based on LAMMPS. NPGrowth enables us to simulate seed-mediated growth under a variety of conditions, even mimicking growth under extreme conditions. It allows one-by-one or N-by-N deposition, either when the incoming atoms are from uniformly distributed or well-defined and fixed spatial regions, onto selected targets, including those reminiscent of a chiral molecule. Moreover, NPGrowth enables the formation, through sintering, of two or more seeds, be that directional, soft-landed or through coalescence. After presenting a few toy models, we discuss the effect of directionality during the sintering of four Cu icosahedral seeds and the importance of identifying the sintering geometry following a pySNOW characterisation and classification.

Nanomaterials doi: 10.3390/nano16211382

Authors: Robert M. Solomon Corneliu I. Oprea Mihai A. Gîrțu

Elastic response affects TiO2 nanostructure durability and performance and depends on particle size and morphology. We determine effective elastic coefficients, moduli, and anisotropy indices from clamped-ion density functional theory energy–strain calculations for nine anatase-derived clusters containing 10–165 Ti atoms, using a tetragonal-form model. Comparing framework convex-hull, hydroxyl-inclusive convex-hull, and bulk-equivalent volumes shows that normalization can create or reverse apparent size trends. Across all five matched parent–cut pairs, cutting and passivating the apices reduces axial stiffness relative to in-plane stiffness and increases relative in-plane coupling and shear. These directional changes are independent of the volume convention. Cutting removes asymmetric axial Ti environments, while hydroxylation satisfies local coordination without restoring the removed framework connectivity. After cutting, mean Ti–O distances shorten, their dispersion narrows, and the mean bond order around 4-coordinate Ti increases, whereas axial stiffness decreases relative to in-plane stiffness. Thus, local bond strengthening coexists with reduced relative axial stiffness. The frontier-orbital gap widens with increasing 4-coordinate Ti fraction and shorter mean Ti–O bonds, while coordination-resolved electronic descriptors also track effective stiffness and anisotropy. These descriptor associations remain exploratory because size, morphology, coordination, and passivation are coupled. Meaningful comparisons of nanocluster elasticity must therefore specify the volume convention and distinguish local bond strengthening from changes in directional stiffness.

Nanomaterials doi: 10.3390/nano16211381

Authors: Tangyi Li Xiaonian Liu Zhiyang Wu Xinjie Tang

Aiming at the challenges of complex structural parameter spaces, excessively time-consuming full-wave electromagnetic simulations, and the tendency of traditional optimization algorithms to fall into local optima in radio frequency integrated circuit (RFIC) on-chip passive inductor design, this paper proposes an automated modeling, surrogate model, and PSO-GA hybrid optimization framework based on full-wave simulation. First, automated parametric modeling and efficient interaction with full-wave solvers are achieved through dedicated scripting interfaces. Second, a high-precision surrogate model is constructed using a physical component decoupling mechanism and Gaussian Process Regression (GPR), with the coefficient of determination (R2) for each physical component exceeding 0.970. Finally, a hybrid optimization strategy integrating Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) is implemented to perform rapid inverse design under target inductance and quality factor constraints. The experimental results show that the error between the inductance and quality factor values predicted by the surrogate model and the target inductance and quality factor values is less than 1%.

Nanomaterials doi: 10.3390/nano16211380

Authors: Grzegorz Matyszczak

Nanotechnology is a rapidly developing and relatively young subdiscipline of science and engineering. It mainly deals with the preparation, characterization and utilization of nanoparticles—particles of size ranging from 1 to 100 nm. The manipulation of such small objects is demanding and the phenomena involved on the nanoscale are relatively complex, and different, compared with their counterparts at both quantum- and macroscales. Further development of nanoscience requires applications and evolution of mathematical models of nanoscale phenomena, preferably with the aid of advanced mathematical methods such as the ordinary and partial differential equations. This review presents the methodology of usage, along with the applications, of differential equations of various types (ordinary, partial, stochastic) to the nanoscale phenomena, including nanoparticles growth, aggregation, properties, and applications.

Nanomaterials doi: 10.3390/nano16211379

Authors: Chao Wang Aiwu Yu Yuzhu Pan Yulian Zhang Jinbao Chen Xin Wang

While CH3NH3PbBr3 (MAPbBr3) single crystals exhibit exceptional potential for biased X/γ-ray detection, achieving a stable metal–semiconductor contact remains a critical challenge. Herein, we address this issue by incorporating AgBr as a dopant into pristine MAPbBr3 single crystals prior to Ag electrode deposition. Our results reveal a concentration-dependent interfacial mechanism: while low-level doping introduces excess Br− ions and Pb vacancies that accelerate electrochemical corrosion, a high concentration of Ag+ within the lattice effectively suppresses the deleterious reaction between the Ag electrode and the perovskite. This work establishes a defect-engineering strategy to stabilize metal electrodes, offering a viable pathway for the development of reliable, high-performance MAPbBr3-based radiation detectors.

Nanomaterials doi: 10.3390/nano16211378

Authors: Benedict Raphael Soesanto Lee Zhi Szen Jason Chua Teng Sern Lee Jing Xian Ha Shou Yi Sachin Sharma Ashok Kumar

High-entropy alloys (HEAs) are revolutionary materials containing five or more primary elements in near-equiatomic amounts to produce an alloy with high configurational entropy that stabilizes at a simple solid solution. Unlike conventional alloys, which are based on one dominant element, HEAs represent a novel advanced material that has shown great properties. These properties are the reason for scientific interest, as they have potential industrial applications due to their exceptional mechanical, thermal, and chemical properties. This paper aims to explore the different rules and principles that dictate their phase formation, including the thermodynamic and kinetic factors that are involved in the development of their phases and nanostructures. The four key effects associated with HEAs will also be explored: the high-entropy effect, severe lattice distortion effect, sluggish diffusion effect, and cocktail effect. The relationship between their unique phase formations and nanostructures and their properties will be discussed, with a view to optimizing them to prioritize certain properties for targeted applications. The mechanisms that occur and dictate these effects on the HEA for its strengthening and deformation will be analyzed to identify the benefits and trade-offs associated with modifying alloy composition and processing parameters. The fabrication methods for different types of HEAs will be reviewed along with current and emerging industrial applications of HEAs, especially in fields that require superior mechanical performance and environmental resistance. Thus, this review highlights their behavior, optimization, and potential applications as the next generation of materials.

Nanomaterials doi: 10.3390/nano16211377

Authors: Mingyu Geng Qinghua Wang Yunjing Ji Jiancheng Lai Zhenhua Li

Polarization sensitivity and limited tunability remain important challenges for high-Q terahertz (THz) metasurfaces based on quasi-bound states in the continuum (q-BICs), particularly when geometric perturbations are introduced to enable radiative coupling. Here, we numerically demonstrate a graphene-integrated all-dielectric THz metasurface that combines high-Q q-BIC resonances, polarization robustness, electrical tunability, and refractive-index sensing through a C4-symmetric supercell design. Each metamolecule consists of two orthogonal amorphous-silicon strips, in which a width perturbation δ introduces local geometric asymmetry and enables the symmetry-protected states to couple to free space, while the four metamolecules related by successive 90° rotations preserve the global C4 rotational symmetry. Two q-BIC modes are supported, with their Q factors exhibiting the characteristic inverse-square dependence on δ. Multipolar analysis reveals that the lower-frequency q-BIC is dominated by magnetic-quadrupole radiation, whereas the higher-frequency mode is primarily governed by toroidal-dipole radiation and exhibits weaker overall radiative leakage. Owing to the C4-symmetric arrangement, the resonance spectra remain nearly invariant for normally incident linearly polarized THz waves over polarization angles from 0° to 90°. Integration of monolayer graphene further enables continuous electrical modulation of the resonance contrast and Q factor by varying the Fermi level from 0 to 0.7 eV, while inducing only minor resonance-frequency shifts. For bulk refractive-index sensing, the two q-BIC modes achieve sensitivities of 345 and 475 GHz/RIU, with maximum figures of merit exceeding 800 and approaching 104, respectively. These results provide a versatile strategy for integrating polarization-robust high-Q resonances, electrical reconfigurability, and high-performance refractive-index sensing in THz metasurfaces.

Nanomaterials doi: 10.3390/nano16211376

Authors: Ling-Yi Ding Wan-Shan Shen Feng Zhao Ya-Kun Wang Liang-Sheng Liao

Indium arsenide (InAs) quantum dots (QDs) offer a promising Pb- and Hg-free material platform for infrared optoelectronics owing to their narrow bulk bandgap, strong quantum confinement, and size-tunable optical response. However, surface defects, limited electronic coupling in quantum dot (QD) solids, and operational instability can prevent advances in material quality from translating into improved device performance. This review examines InAs QDs through a materials-interface-device-performance framework. We first discuss how synthetic control, core/shell heterostructures, ligand exchange, and surface reconstruction influence interfacial electronic states and carrier dynamics. We then analyze device-specific performance and trade-offs in solar cells, quantum dot light-emitting diodes, infrared photodetectors, and field-effect transistors, focusing on charge injection and extraction, trap-assisted losses, noise, and stability. Finally, we identify emerging opportunities in contact engineering, reliable performance benchmarking, scalable film fabrication, and advanced infrared device architectures. This device-oriented perspective emphasizes the role of coordinated interface engineering in connecting nanocrystal properties with functional optoelectronic performance.

Nanomaterials doi: 10.3390/nano16211375

Authors: Jianyang Zhou Guiyu Zhang Haiqing Liu Genge Zhang Qingqing Chang Caigui Huang Xiaoping Luo

The instability of nanofluids leads to particle agglomeration and sedimentation, which clog the heat transfer channels and deteriorate the overall performance of heat exchangers. Accordingly, preparing uniformly dispersed and structurally stable nanofluids serves as a fundamental prerequisite for their practical engineering applications. In this study, refrigerant R141b was selected as the base fluid, and graphene/R141b nanofluids were prepared via a two-step method assisted by ultrasonic oscillation. The effects of ultrasonic oscillation time, dosage of surfactant, and nanoparticle mass concentration on the stability of graphene/R141b were systematically investigated, and zeta potential, DLS particle size, Raman and XRD analysis were used to evaluate the stability of graphene/R141b. The experimental results demonstrate that ultrasonic oscillation time and nanoparticle mass concentration both exert significant influences on the stability of graphene/R141b nanofluid. The SDS surfactant can effectively improve the stability of the prepared graphene/R141b nanofluid. In conclusion, under the conditions of adding SDS surfactant and carrying out ultrasonic oscillation within 120–150 min, graphene/R141b with a mass concentration ranging from 0.05% to 0.4% exhibits satisfactory stability, while excessively prolonged sonication (180 min) reduces the stability of the nanofluid, which provides a promising candidate for future validation of heat-transfer-enhancement performance in heat-exchanger applications.

Nanomaterials doi: 10.3390/nano16211372

Authors: Guang Hu Tingting Zhou Jing Tang Kuankuan Liu Ge Zhao Junqi Wang

Irradiation has long been regarded as a major source of degradation in metallic materials because energetic particles continuously generate irradiation-induced defects that lead to hardening, embrittlement, swelling and creep. Beyond its detrimental effects, irradiation has long been employed to modify material microstructures and properties. More recently, increasing attention has been directed toward understanding and deliberately controlling irradiation-induced defect evolution to regulate material properties within a broader defect-engineering framework. This review systematically summarizes the fundamental damage mechanisms induced by irradiation in metallic materials, with particular emphasis on irradiation hardening, embrittlement, swelling and creep. Subsequently, advances in the functional utilization of irradiation-induced defects are reviewed from three perspectives: structural modification and mechanical property enhancement, irradiation-regulated magnetic properties, and surface and interface functionalization. Representative studies demonstrate that irradiation can effectively induce nanocrystallization, refine microstructures, regulate magnetic anisotropy and Curie temperature, and improve corrosion resistance, wear resistance and biocompatibility through controllable defect engineering. Finally, the remaining challenges associated with defect controllability, quantitative structure–property relationships and engineering implementation are discussed, together with future opportunities enabled by advanced characterization, multiscale modeling and intelligent materials design. This review highlights the dual role of irradiation as both a source of material degradation and a versatile tool for microstructural and functional regulation, providing useful guidance for the development of next-generation structural and functional metallic materials for applications in nuclear energy, aerospace, biomedical engineering and advanced manufacturing.

Nanomaterials doi: 10.3390/nano16211374

Authors: Kaiyan Cao Kun Cao Yiran Wang Fanghua Tian Chao Zhou Qizhong Zhao Minxia Fang Yu Wang Yin Zhang Sen Yang

Low-cost, sustainable thermal insulation materials are needed for energy-efficient thermal management. Here, porous rice husk char (RHC) was produced from agricultural waste by pyrolysis at 300, 500, and 700 °C. RHC/polyvinylidene fluoride (PVDF) composite films were then prepared by blade coating where feasible. We examined how pyrolysis temperature affected char structure, carbon disorder, film morphology, and thermal transport. RHC-300-16 did not form an intact self-supporting film under the processing conditions used. RHC-700-16 contained coarser agglomerates and larger visible voids than RHC-500-16. RHC-500-16 exhibited a higher BET specific surface area (3.1347 m2·g−1) and total pore volume (0.007716 cm3·g−1) than RHC-700-16 (1.9471 m2·g−1 and 0.003153 cm3·g−1, respectively), with average BJH pore diameters of 33.30 and 21.66 nm, respectively. RHC-500-16 had a room-temperature thermal conductivity of 0.059 W·m−1·K−1. In a qualitative 100 °C heating-stage test, RHC-500-16 exhibited a lower surface temperature than a thickness-matched paper control. The measured thermal conductivity was associated with the combined effects of pore characteristics, film morphology, interparticle contacts, and carbon structure. These results link pyrolysis temperature to char structure and composite-film thermal conductivity in biomass-derived insulation films.

Nanomaterials doi: 10.3390/nano16211371

Authors: Nicolò Rimondotto Alice Rossi Matteo Pavese Luca Lavagna

Cement-based materials are among the most widely used substances in the construction industry owing to their widespread availability and reliable performance. However, their quasi-brittle behavior and limited tensile capacity often lead to the initiation and propagation of microcracks, which can compromise durability and structural integrity. In this context, the incorporation of carbon nanotubes (CNTs), owing to their exceptional stiffness and strength, has emerged as a promising strategy to enhance the mechanical performance of cementitious matrices and mitigate their intrinsic brittleness. This comprehensive review critically assesses the reinforcing mechanisms associated with CNT addition, with particular emphasis on hydration promotion and nucleation effects, pore-filling and microstructural densification, CNT–matrix interfacial interaction and crack propagation inhibition. Furthermore, this work critically examines modeling approaches for predicting the mechanical properties of CNT-reinforced cementitious composites, including analytical formulations, numerical methods and recent advances based on machine learning and artificial intelligence. This review aims to consolidate the current state of knowledge while highlighting current limitations and outlining future research directions for the development of high-performance cementitious composites.

Nanomaterials doi: 10.3390/nano16211373

Authors: Andergachew Mekonnen Berhe Hao Wu Haroldo T. Hattori Andrey E. Miroshnichenko

Metasurface–transition metal dichalcogenide (TMDC) monolayer hybrids are a promising platform for strong coupling and compact quantum nanophotonic devices. In this review, we discuss the main theories, design approaches, recent experiments, and applications of these systems, focusing on single-photon emission and lasing. We explain how the mode volume and quality factor work together in these systems. Dielectric and plasmonic metasurfaces provide different balances of optical loss and field confinement. Because the reported systems differ in TMDC material, temperature, exciton linewidth, and field overlap, their Rabi splittings alone cannot establish an intrinsic ranking of the two platforms. In the strong coupling regime, polariton nonlinearities could enable photon blockade and high-purity single-photon emission, but achieving this at room temperature is still mostly theoretical. Photon lasing has been shown in metasurface–TMDC systems, but clear evidence of polariton lasing from a TMDC monolayer combined with dielectric or plasmonic metasurfaces is still missing. The main challenges include exciton–exciton annihilation and weak mode overlap in dielectric structures, as well as very short photon lifetimes in metallic resonators. Finally, we discuss experimental benchmarks and the scalable cleanroom fabrication of high-Q plasmonic metasurfaces, including dielectric metasurfaces. These are applicable to room-temperature, directional, ultrafast, and energy-efficient nanoscale light sources. Furthermore, low-loss dielectric metasurfaces are summarised for manipulating the generated emitted light, which is crucial for directing and manipulating the light on-chip and for directly collimating and aligning it with an optical fibre.

Nanomaterials doi: 10.3390/nano16211370

Authors: Freddy Escobar-Teran Kleber Andrade

The intermittent nature of renewable energy sources requires efficient energy storage technologies to prevent losses. Supercapacitors are key devices for these applications due to their high power density and rapid electrostatic storage capabilities. This review summarizes recent advances in electrochemical and simulation-based methods used to study charge storage at the electrode/electrolyte interface. We examine ion transport kinetics, species identification, and the solvation and desolvation dynamics that govern the electrochemical process. Finally, we provide a critical assessment of current analytical methodologies and outline future perspectives, emphasizing that the synergy between computational methods and experimental techniques will drive the development of next-generation supercapacitors with enhanced performance.

Nanomaterials doi: 10.3390/nano16211369

Authors: Angiee C. Jiménez-Oñate Ana B. González-Rojas Edgar D. Peduzine-Orozco Juan P. Molina-Jiménez Duber A. Avila Sindi D. Horta-Piñeres

Post-synthesis heat treatment provides a route for tuning the structural and optical response of TiO2 without necessarily altering its particle architecture. In this study, TiO2 nanostructures prepared by the sol–gel method were evaluated before and after a stepwise heat treatment from 250 to 400 °C using XRD/Rietveld, Raman spectroscopy, FE-SEM/EDS, statistical morphometry, and UV–Vis diffuse reflectance spectroscopy, with XPS performed on TiO2-400. TiO2-250 consisted of 96.76 ± 1.22 wt.% anatase and 3.24 ± 0.47 wt.% brookite, whereas anatase was the only crystalline phase detected in TiO2-400 within the XRD detection limit. Concurrently, the coherent crystalline domain size increased from 44.3 ± 2.6 to 53.6 ± 1.9 nm, without a statistically significant increase in the equivalent circular diameter of the particles. The apparent optical band gap increased from 3.14 ± 0.03 to 3.25 ± 0.03 eV, while the Urbach energy decreased by approximately 48%, from 189.4 ± 1.1 to 98.0 ± 0.4 meV. These results show that moderate heat treatment is accompanied by polymorphic homogenization and predominantly intraparticle crystalline/electronic reorganization, together with narrowing of the band-tail distribution without appreciable external particle growth. Overall, the study establishes a multiscale correlation between phase evolution, coherent-domain growth, morphological stability, and optical-edge narrowing in sol–gel TiO2 nanostructures.

Nanomaterials doi: 10.3390/nano16211368

Authors: Changzeng Yan Xiang Li Zeyu Dong Guiying Li Xiuhua Ma Yuhan Zhang Guangqi Bai Dae Joon Kang

Severe heat buildup within chips limits device stability and service life, and thermally conductive yet electrically insulating polymer nanocomposites become critical thermal interface materials (TIMs) for electronics cooling. The intrinsic interfacial thermal resistance (ITR) between discrete thermally conductive fillers in TIMs remains the core bottleneck limiting thermal conductivity improvement, and rationally constructing three-dimensional (3D) interconnected filler networks represents a feasible and efficient strategy to address this issue. Inspired by the natural hierarchical point–line–plane topological skeleton of a plant leaf, which realizes efficient internal matter transfer via long spicular lines, discoid planar scaffolds, and vein nodes, we design and produce a novel BNNT/WS2/Ag ternary hybrid thermally conductive network within an epoxy matrix. Specifically, high aspect ratio boron nitride nanotubes (BNNTs) act as one-dimensional linear thermal conduction skeletons mimicking leaf veins, while tungsten disulfide (WS2) nanosheets serve as two-dimensional planar heat-collecting and heat-spreading scaffolds with large specific surface areas. Notably, in situ photodeposited silver (Ag) nanoparticles function as biomimetic vein nodes between adjacent fillers. Low-temperature sintering enables these Ag nodes to tightly connect BNNT linear skeletons and WS2 planar nanosheets, effectively bridging isolated thermal conductive units, which is expected to reduce the effective thermal resistance of the composite system. This hierarchical point–line–plane structure constructs a continuous, unobstructed 3D thermal conduction highway inside the epoxy matrix. The resultant BNNT/WS2/Ag/epoxy nanocomposite exhibits excellent thermal conduction performance, with a prominent in-plane thermal conductivity of 21.5 W m−1 K−1 and a high through-plane thermal conductivity of 7.63 W m−1 K−1. Benefiting from the hierarchical topological structure and interconnected conductive network, the as-prepared nanocomposites possess outstanding heat dissipation capability and hold great promise for high-efficiency thermal management in advanced electronic devices.

Nanomaterials doi: 10.3390/nano16211367

Authors: Yuanqingqing Tao Ziyi Hao Yi Zhang Guo Li Baizeng Fang

Flexible wearable sensors increasingly use nanomaterials and nanoscale interfaces to acquire biomechanical, electrophysiological, and biochemical signals during sports and rehabilitation, where repeated deformation, perspiration, and variable body contact challenge measurement stability. This review examines how the nanomaterial architecture and body–sensor interface design influence signal reliability under dynamic operating conditions. Carbon nanomaterials, MXenes, conductive polymers, metallic nanostructures, and soft nanocomposites are discussed together with matrices and fibrous supports that regulate their mechanical and chemical interfaces. Emphasis is placed on the links between nanoarchitecture, transport behavior, interfacial coupling, and major transduction routes. Representative applications in motion monitoring, exercise physiology, sweat analysis, and rehabilitation are then assessed in terms of signal stability and physiological interpretability. The literature indicates that sensitivity alone is an incomplete measure of wearable performance because working range, hysteresis, adhesion, sampling variability, and calibration drift often become limiting factors under repeated use. Reliable sensing depends on preserving a stable relationship between the target stimulus and sensor output across realistic operating conditions. Future work should focus on robust nanoarchitectures, adaptive body–sensor interfaces, application-specific calibration, and validation under combined mechanical and environmental loading.

Nanomaterials doi: 10.3390/nano16211366

Authors: Jesús López-García Eric Medrano-Sánchez Ricardo López-Rodríguez Ever Blé-González Ammy Gallegos-García Nelly Aguilar-Sánchez María Escalante-Pérez Felipe Córdova-Lozano Gerardo Córdova-Pérez Alejandro Bugarin Patricia Álvarez-Fitz Adrián Cervantes-Uribe Abraham Gómez-Rivera

ZnO nanoparticles were synthesized through a bio-assisted route using a hydroalcoholic extract of Tradescantia spathacea Sw., a plant previously reported to exhibit antimicrobial activity. Zinc acetate dihydrate [Zn(CH3COO)2·2H2O] was used as the precursor, and the resulting materials were subjected to different thermal treatments (room temperature, 50, 100, 200, and 500 °C) to evaluate changes in their physicochemical and biological properties. The samples were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption–desorption, UV–Vis diffuse reflectance spectroscopy, and zeta-potential measurements. Their interaction with 4-nitrophenol (4-NP) under dark conditions was also evaluated as a molecular probe of the solid-solution interfacial environment. Antimicrobial activity was assessed against bacterial and fungal microorganisms, while anti-virulence activity was evaluated through the inhibition of swarming motility in Proteus mirabilis 884. FT-IR analysis showed that organic species derived from the extract remained in the materials treated between room temperature and 200 °C, whereas these contributions disappeared after treatment at 500 °C. XRD confirmed the formation of the hexagonal wurtzite ZnO structure in all samples, while SEM revealed changes in morphology from agglomerated flake-like structures toward more defined particles. Zeta-potential measurements showed distinct negative electrokinetic behavior among the materials, indicating differences in their interfacial surface environments. In addition, contact with 4-NP modified its protonation equilibrium and produced spectral changes compatible with surface-mediated oxidative transformations under dark conditions. The ZnO materials exhibited antimicrobial activity, with a MIC of 320 μg/mL against P. mirabilis 884, and markedly inhibited its swarming motility, reaching more than 96% inhibition for one sample at 24 and 48 h. Overall, the results indicate that the bio-assisted synthesis modifies the surface properties of ZnO and support a surface-mediated mechanism in which changes in the interfacial microenvironment and oxidative processes may contribute to microbial inhibition.

Nanomaterials doi: 10.3390/nano16211365

Authors: Amjad Almuqrin Chaminda Jayampath Seneviratne Laurence J. Walsh Sobia Zafar

Purpose: To evaluate the 12-month physicochemical stability of silver and selenium nanoparticles (NPs) fabricated initially for topical caries arrest. Materials and Methods: The nanoparticles were synthesised via chemical reduction and capped with naturally derived agents. Post-synthesis suspensions were washed and stored at 4 °C in the dark for 12 months. Stability was assessed by comparing the physicochemical properties at baseline and 12 months. The characterisation approaches included Tyndall scattering and UV–visible spectroscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectroscopy. Results: As formulations aged, they showed differences in stability. Citrate-capped silver NPs (AgL1) retained a defined surface plasmon resonance and showed a 6.7% reduction in elemental concentration. Silver NPs capped with casein (Ag1) and bovine serum albumin (Ag2) showed moderate reductions in elemental concentration (26.9% and 54.8%, respectively), accompanied by the formation of larger particle populations (~20–40 nm). Their initial mean particle sizes were 3.6 ± 3.4 nm for Ag1 and 2.5 ± 0.8 nm for Ag2. In contrast, silver NPs capped with citrate and tannic acid (AgL2) exhibited a substantial reduction in elemental concentration (88.6%), accompanied by pronounced particle aggregation. Selenium nanoparticles were the least stable: UV–Vis absorption features collapsed, TEM showed agglomeration (>70–100 nm), and ICP–OES indicated a significant reduction in the measured elemental concentration in the analysed suspension especially in Se1 (99.9%) and Se2 (99.96%). Conclusions: Under refrigerated, dark storage for 12 months, citrate-capped silver nanoparticles showed preserved integrity, whereas others showed moderate to severe issues with colloidal and elemental stability.

Nanomaterials doi: 10.3390/nano16211364

Authors: Keke Xu Yongkang Sun Lichao Tan Mingzhu Zhang Wenming Pei Ziyan Du Jiqiang Jia Xiaoyan Zhang Jingjing Yun Feng Ge Lei Wang Ningyuan Zhu

Perchlorate (ClO4−) is kinetically persistent in aqueous environments because of its highly symmetric tetrahedral structure and the high activation barrier for Cl−O bond cleavage. Although nanoscale zero−valent iron (nZVI) is a strong reductant, particle aggregation, surface passivation, and inefficient interfacial electron transfer limit its reactivity toward ClO4−. Here, a mesoporous nZVI@Mg(OH)2 core–shell−like composite was fabricated by a one−step liquid−phase in situ deposition strategy to couple substrate accessibility with interfacial electron transfer. At a nominal Mg(OH)2/nZVI mass ratio of 10%, the Mg(OH)2−modified composite showed substantially reduced particle aggregation and increased the BET specific surface area from 4.57 to 67.29 m2·g−1 and the pore volume from 0.0242 to 0.2542 cm3·g−1. The hydroxylated Mg(OH)2 interface may additionally favor local ClO4− accumulation under acidic−to−near−neutral conditions. Under benchmark conditions, the system removed 98.37% of 10 mg·L−1 ClO4− from the aqueous phase within 48 h. The reaction also showed an apparent activation energy of 50.96 ± 6.04 kJ·mol−1. XRD, Raman, and XPS analyses showed progressive Fe0 consumption and the development of a Fe3O4−dominated crystalline reaction layer with a more oxidized and hydroxylated Fe(III)−rich outer region, providing independent evidence for a strongly reducing and dynamically reconstructed Fe−containing interface. Electrochemical measurements revealed a substantially more negative open−circuit potential for nZVI@Mg(OH)2, while equivalent−circuit fitting showed that the total polarization resistance decreased from 15.21 to 10.78 kΩ relative to bare nZVI, consistent with a more electrochemically accessible interface. In situ OCP measurements further showed an immediate electrochemical response upon ClO4− addition. Together with TBA scavenging and Fe2+ control experiments, these results support a predominantly heterogeneous interfacial transformation process and are consistent with a major contribution from direct interfacial electron transfer. The enhanced reactivity is attributed to the coupling of improved substrate accessibility with an electronically accessible, low−resistance Fe−containing interface. This work provides a mechanistic basis for the interfacial design of Fe−based materials with coordinated mass−transport and electron−transfer characteristics toward kinetically persistent oxyanions.

Nanomaterials doi: 10.3390/nano16211363

Authors: Jinhua Zhuang Heshan Cai Sibo Ding Zekai Liu Haopeng Liao Haoze Jiang Yuyue Luo Chaoming Liang Hang Zhang Songran Guan Daguang Li

As a metal-free, visible-light-responsive two-dimensional (2D) layered semiconductor, graphitic carbon nitride (g-C3N4) has been extensively studied for photocatalytic water purification owing to its high chemical stability, facile synthesis, and low cost. However, single-phase g-C3N4 still suffers from bottlenecks including rapid photogenerated electron–hole pair recombination, low visible-light utilization efficiency, insufficient specific surface area, and a limited number of exposed surface active sites, which severely restrict its practical photocatalytic performance. Rational construction of heterojunctions with matched band alignment and intimate interfacial contact serves as an effective strategy to boost the photocatalytic activity of g-C3N4. This review introduces the structural characteristics and photocatalytic mechanisms of g-C3N4, summarizes the primary types of g-C3N4-based heterojunctions along with their charge transfer pathways, and highlights recent research progress in emerging contaminant degradation, pathogenic microbial disinfection, and reduction of high-valence and highly toxic heavy-metal ions for water decontamination. The review closes with critical perspectives on the rational design and practical engineering prospects of g-C3N4-based heterojunctions. By bridging heterojunction mechanisms with water-purification applications and engineering considerations, this review is expected to guide the rational design of high-performance g-C3N4-based heterojunctions and accelerate their translation toward practical water purification.

Nanomaterials doi: 10.3390/nano16211362

Authors: Xiangxiang Yu Junkang Chen

Selected van der Waals magnets retain magnetic order down to the monolayer limit. Their sensitivity to layer number, local bonding, carrier density, and interfaces provides routes to magnetic control for spintronic and quantum devices. In this review, we focus on the control of magnetism in representative two-dimensional systems and organize the field from the perspective of structure–property relations and matched control strategies. We show that weak interlayer exchange enables magnetic-field switching in few-layer magnets, that spin-layer locking supports electric-field control in bilayer CrI3, that doping-sensitive exchange allows carrier-density tuning in CrI3 and Fe3GeTe2, that stacking-dependent interlayer coupling makes pressure and twist effective structural knobs, that strong magnetoelastic coupling gives strain direct access to magnetic phase boundaries, and that interfacial exchange and proximity effects turn van der Waals heterostructures into active platforms for engineering emergent magnetic states. Representative material families are discussed in this context, including chromium trihalides, phosphorus chalcogenides, Ge- and Te-based layered magnets, transition-metal chalcogenides, MnBi2Te4-family compounds, and oxyhalides. Together, these studies show that the field is evolving from the discovery of intrinsic two-dimensional magnets toward the mechanism-guided design of controllable magnetic phases, magnetic heterostructures, and functional spintronic and quantum devices.

Nanomaterials doi: 10.3390/nano16211361

Authors: Ekaterina A. Kolobova Andrei I. Demenshin Yulia P. Zimarina Elena V. Solovyeva

Utilizing state-of-the-art nanomaterials for chiral discrimination is an emerging area of analytical research. Herein, we explored for the first time, metal nanoclusters as a chiral selector in capillary electrophoresis. Vancomycin-stabilized copper nanoclusters (CuVanc NCs) were intentionally synthesized, purified and characterized by UV-Vis and fluorescence spectroscopy, transmission electron microscopy, dynamic light scattering, and X-ray photoelectron spectroscopy. The 5-step sequential protocol of solid-phase extraction was designed to isolate CuVanc NCs from the as-synthesized solution before electrophoretic experiments. The recovery was found to be over 90%. The purified CuVanc NCs were utilized as a chiral discriminator for enantioselective recognition of model drugs. The effects of key parameters, including the pH value of the running buffer and concentration of CuVanc NCs, were assessed. Chiral separation was successfully achieved for both positively and negatively charged analytes, with the better enantioselectivity observed for amlodipine (α = 1.017) and acenocoumarol (α = 1.015), respectively. The separation behavior was strongly influenced by the background electrolyte pH and nanocluster concentration, balancing electrostatic interactions and electrophoretic mobility. Overall, the study highlights a high potential of metal nanoclusters as effective chiral selectors in capillary electrophoresis, opening up new opportunities for chiral analysis and pharmaceutical quality control.

Nanomaterials doi: 10.3390/nano16211359

Authors: Shen Mao Pengwei Fang Yan Zhu Qun Zhang Meiwen Cao

As global warming intensifies, carbon dioxide (CO2) has become one of the primary contributors to climate change. Carbon capture, utilization, and storage (CCUS) technology represents one of the most effective methods for reducing CO2 emissions, offering a promising solution by capturing CO2 and either utilizing it or storing it in underground reservoirs for long-term sequestration. Among various CCUS strategies, CO2 geological utilization and storage (CGUS), which focuses on the geological aspects of CO2 storage and its potential utilization, plays a pivotal role. However, existing CGUS technologies still face challenges, including high costs and low efficiency. To enhance CGUS efficiency, the development of innovative technologies and materials is essential for improving the overall capability of the processes. Nanomaterials are increasingly recognized as an ideal solution for enhancing CGUS technology due to their ultra-small size, high specific surface area, exceptional physical and chemical properties, and potential for functionalization. This review examines the latest advancements in the application of nanomaterials for CGUS, focusing on the characteristics and potential of metal oxide nanomaterials, carbon-based nanomaterials, and inorganic nanomaterials, particularly silicon dioxide (SiO2). It also addresses the technical challenges that hinder the practical implementation of nanomaterials, including issues related to stability, scalable production, and environmental risks. Furthermore, the article outlines key research challenges and future directions for advancing CGUS technologies. The aim of this review is to provide a theoretical foundation and technical insights to drive innovation in CGUS technology.

Nanomaterials doi: 10.3390/nano16211360

Authors: Shijie Duan Jiahao Chen Changqin Liu Xiaojuan Yuan Yifei Li Jinguang Wang Xin Lu Dongdong Kang Jiayu Dai Xiaoxiang Yu

Probing the interfacial thermal transport under extremely large temperature difference (ELTD) is critical for thermal protection and heat dissipation in extreme environments yet challenging. However, conventional optical thermoreflectance methods work only over narrow temperature ranges and thus fail for ELTD conditions characterized by a broad temperature evolution range. Here, we circumvent this limitation by employing a table-top ultrafast X-ray diffraction (UXRD) system, which exploits the nearly linear lattice thermal expansion over a wide temperature range. We investigate interfacial thermal transport in a W thin film on a MgO substrate under ELTD conditions and determine that the interfacial thermal conductance (ITC) value increases from 6.43 × 108 W m−2 K−1 to 8.71 × 108 W m−2 K−1 as the maximum temperature of W rises from 670 K to 2334 K, accompanied by an increase in the maximum interface temperature difference from 302 K to 1451 K based on the finite volume method (FVM). The results reside at a relatively high level among reported ITC values for conventional metal-oxide interfaces, which may originate from the simultaneous increase in interface temperature difference and mean interface temperature. This work demonstrates UXRD as an effective tool for ELTD thermal measurements and fills a critical knowledge gap regarding interfacial thermal transport under extreme conditions.

Nanomaterials doi: 10.3390/nano16211357

Authors: John Anthuvan Rajesh Shrine Maria Nithya Jeghan Soon-Hyung Kang Kwang-Soon Ahn

We report the facile synthesis of Ni0.85Se nanosheet arrays directly grown on nickel foam (NF) via a two-step hydrothermal strategy using Ni(OH)2 as a precursor. The two-dimensional architecture offers abundant electroactive sites and efficient charge transport pathways, resulting in remarkable electrocatalytic activity toward the urea oxidation reaction (UOR). The optimized Ni0.85Se/NF electrode delivers a current density of 10 mA cm−2 at a potential of 1.352 V vs. RHE and exhibits a small Tafel slope of 42.3 mV dec−1. Furthermore, it demonstrates excellent durability, maintaining stable operation for over 120 h in alkaline urea-containing electrolyte. These findings highlight Ni0.85Se nanosheets as a cost-effective and durable non-noble-metal electrocatalyst with significant potential for urea oxidation application.

Nanomaterials doi: 10.3390/nano16211358

Authors: Elena Tatarova Neli Bundaleska Edgar Felizardo Ana Dias Antonio Silva Miroslav Abrashev Jivko Kissovski Janez Zavašnik Uroš Cvelbar Nenad Bundaleski Orlando M. N. D. Teodoro Amelia Almeida Milena Georgieva Todor Karadimov Bruno Gonçalves

Here, a plasma-enabled strategy is presented for the controllable fabrication of ultralight nanocomposites with absorption-dominated EM-shielding performance across the 5–70 GHz frequency range. The fabricated nanocomposites exhibit average microwave absorption exceeding 60% across the 5–25 GHz frequency range and 70% across the 25–70 GHz range while maintaining a constant thickness of 2 mm and a fixed filler content of 15 wt%. Plasma-driven nanoscale engineering and multiphase hybridization synergistically enhance dielectric and magnetic loss mechanisms, resulting in effective absorption bandwidths in the C-band (2.1 GHz), Ku-band (3.4 GHz), Ka-band (8 GHz) and V-band (4 GHz). The plasma process produces free-standing nitrogen-doped graphene sheets uniformly decorated with FexOy, MnOx, and TiOx nanoparticles, which are subsequently incorporated into a polymer matrix. The microwave plasma environment simultaneously enables graphene nanosheet synthesis, metal oxide nanoparticles formation, surface functionalization, multiphase generation, and the anchoring of nanoparticles onto the graphene scaffold. Using low-cost precursors such as acetonitrile and micron-sized metal oxides, the process achieves production rates of up to 50 mg min−1. Overall, this one-step plasma-enabled approach provides a low-cost, scalable, and efficient route for manufacturing lightweight, high-performance EM wave absorbers.

Nanomaterials doi: 10.3390/nano16211356

Authors: Mian Sun Yan Sun Linghua Tan Leichong Wang

Recently, hexagonal ferrites (hexaferrites) have attracted increasing attention for high-performance microwave absorption owing to their favorable magnetic and dielectric properties. However, their natural resonance in the GHz region limits their application in narrow-band high-frequency absorbers. Herein, Ce3+-doped BaCo2Fe16O27(CBCF) hexagonal ferrite sheets with varying Ce concentrations were successfully synthesized via a sol–gel method combined with high-temperature calcination. With increasing Ce3+ content, the diffraction peaks shifted towards higher angles, and the magnetic parameters of the W-type hexaferrite were effectively improved. The saturation magnetization increased from 75.66 to 83.73 emu/g. Notably, the Ce0.075Ba0.925Co2Fe16O27(C0.075BCF) sample exhibited excellent broadband absorption performance, achieving a minimum reflection loss (RL) of −18.40 dB at 14.92 GHz and an effective absorption bandwidth of 5.52 GHz. The microwave absorption performance was effectively controlled by tuning the natural resonance frequency of the W-type hexaferrite via Ce doping. This study provides a new strategy for designing broadband microwave absorbers by modulating the natural resonance frequency.

Nanomaterials doi: 10.3390/nano16211355

Authors: Yanan Wang Jintao Cheng Tao Liu Shiyu Li Qingchi Wang Kan Shao Guiling Yang Peiwu Li

The therapeutic landscape for neurodegenerative diseases (NDs), including Alzheimer’s and Parkinson’s disease, remains challenging due to their complex, multifactorial pathogenesis and the limited efficacy of conventional therapies that primarily offer symptomatic relief. The emergence of nanozymes, nanomaterials with intrinsic enzyme-mimicking activities, presents a promising opportunity for multi-targeted intervention. This review comprehensively explores the rational design and therapeutic mechanisms of nanozymes in combating core pathological features of NDs, such as oxidative stress, protein aggregation, and neuroinflammation. We critically assess their remarkable ability to cross the blood–brain barrier and execute synergistic functions, including reactive oxygen species scavenging, misfolded protein degradation, and modulation of microglial activation. Furthermore, we provide a detailed analysis of the application and efficacy of nanozymes across major NDs, alongside a discussion on pharmacokinetics, biosafety, and prevailing challenges. By delineating the structure-enzyme-mimicking activity relationships and cellular-level mechanisms, this review aims to establish a foundational framework for the future development of nanozyme-based neuroprotective strategies, supporting ongoing efforts toward disease-modifying interventions for NDs.

Nanomaterials doi: 10.3390/nano16211354

Authors: Huanbin Zhang Feng Ye Fu Jie Saiqa Menhas Sikandar Hayat Xunfeng Chen Weiping Liu Kashif Hayat

Engineered nanomaterials (ENMs) are used or investigated in sports for mechanical reinforcement, friction regulation, thermal management, biosensing, energy harvesting, and tissue repair. This critical review examines their applications, environmental release, transformation, exposure pathways, biological interactions, and end-of-life management, distinguishing field measurements, laboratory tests, models, and proposed pathways. ENMs are deliberately engineered for nanoscale functionality; microplastics (MPs) and nanoplastics (NPs) are classified by polymer composition and size. Micro(nano)plastics (MNPs) are not inherently nanomaterials; nanoscale polymer particles may be engineered or incidental. MNPs from synthetic turf, polymeric infill, running tracks, footwear, and apparel are assessed as degradation products, potential carriers of embedded ENMs, and co-occurring contaminants. Field evidence is stronger for turf-derived MP release than for sports-related free ENM or NP release. Abrasion, oxidation, and weathering modify particle size, surface chemistry, and sorption capacity, while hydrological runoff, wind transport, and human activities redistribute particles. Athlete exposure through inhalation, ingestion, and dermal contact is plausible, but limited longitudinal biomonitoring warrants cautious interpretation of health risks. Laboratory ecotoxicological studies identify material- and preparation-dependent hazards to terrestrial and aquatic biota, but do not establish effects at measured sports-field drainage concentrations. Sustainability requires low-emission material design, effective physical containment, advanced drainage treatment, environmentally realistic exposure testing, transparent material disclosure, and robust end-of-life recovery systems. Circularity metrics must incorporate diffuse particulate and chemical emissions into life-cycle exposure and ecosystem risk assessments. Comparative synthesis links material properties, release identity, analytical limits, and pathway confidence; a minimum reporting framework identifies the measurements needed for quantitative exposure and risk assessment.

Nanomaterials doi: 10.3390/nano16211353

Authors: Shansong Zhou Hongti Zhang

Layered indium selenide (InSe) is a promising semiconductor for optoelectronic, thermoelectric, and flexible-device applications, for which mechanical reliability is essential to device integration and operation. In this study, the mechanical behavior of β-InSe nanosheets was investigated using device-assisted in situ scanning electron microscopy (SEM) uniaxial tensile testing. Within the investigated thickness range, the first-instability stress generally increased with decreasing thickness, reaching a maximum measured value of 0.972 GPa, while the first-instability strain reached up to 7.383%. Notably, first instability did not lead to immediate complete fracture: some specimens continued to sustain load after initial instability, with the highest final failure strain reaching approximately 19.099%. Experimental results further showed that different portions of the nanosheet thickness fractured sequentially at different spatial locations, leading to progressive failure rather than instantaneous rupture of the entire load-bearing cross-section. These findings provide experimental insight into the thickness-dependent tensile response and progressive failure behavior of layered InSe nanosheets at the micro-/nanoscale.

Nanomaterials doi: 10.3390/nano16211352

Authors: Bozhidar I. Stefanov Lyudmila Krasteva Stanislava Todorova Iliyana Yordanova Simona Delibaltova Hristo Kolev

Tribocatalysis is an emerging approach for the oxidation of organic pollutants using frictional energy. ZnO nanorods were prepared by thermal decomposition of zinc acetate dihydrate and wet-chemically modified with Gd2O3, Dy2O3, or Er2O3. SEM, nitrogen sorption, XRD, ATR-FTIR, Raman spectroscopy, and XPS confirmed the formation of predominantly rod-like ZnO, preservation of its morphology and wurtzite structure after modification, and introduction of nanocrystalline RE2O3 phases. Tribocatalytic activity was evaluated under mechanical stirring using the anionic dye Reactive Black 5 (RB5) and the cationic dye Brilliant Green (BG), examining the effects of RE modification, stirring rate, friction pair, scavengers, and catalyst reuse. Removal increased with stirring rate and was consistently higher for RB5. At 800 rpm, Er:ZnO exhibited the highest activity toward both dyes, reaching approximately 81% RB5 removal (kapp ≈ 0.074 h−1) and 56% BG removal (kapp ≈ 0.040 h−1) after 24 h. COD removal reached 53–60% for RB5 and 27–43% for BG, indicating a reduction in the oxidizable organic load consistent with partial mineralization. ATR-FTIR revealed carbonate formation and PTFE transfer to recovered catalysts, highlighting surface changes and secondary contamination. The results demonstrate measurable tribocatalytic activity and show that the benefits of RE modification depend on the target dye.

Nanomaterials doi: 10.3390/nano16211351

Authors: Sergei V. Yakovlev Stepan Yu. Kupreenko Dmitrii N. Stolbov Anton S. Ivanov Andrey N. Kharlanov Konstantin I. Maslakov Evgeniya V. Suslova Serguei V. Savilov

The influence of modified (oxidized and doped) carbon nanomaterials added to a PVC-based enamel on the kinetics of seawater diffusion into a protective coating has been studied. To this end, the feasibility of using diffuse reflectance infrared spectroscopy and open-circuit potential (OCP) noise measurements of a three-electrode cell for investigating water diffusion kinetics was examined. The applicability of these methods was validated by electrochemical impedance spectroscopy (EIS) measurements. OCP noise and trend line monitoring has potential for broad application due to its simplicity and low cost compared to EIS, as well as its capability for diagnostics of anticorrosion coatings at the earliest stages of water diffusion into the coating. Oxidized few-layer graphene nanoflakes exhibited outstanding barrier properties (low water capacity, low rate of water diffusion into the coating, the high coating resistance and low rate of coating resistance degradation) as components of anticorrosion coatings. This performance is attributed to a high density of oxygen-containing functional groups, which ensure homogeneous nanofiller dispersion and promote strong interfacial adhesion to the polymer matrix via hydrogen bonding.

Nanomaterials doi: 10.3390/nano16211350

Authors: Kailai Zhang Ao Feng Gan Wang Hang Chen Shurui Xu Guoyu Zhong Baizeng Fang

Low-grade mechanical energy widely exists in natural environments, such as ocean-wave fluctuation, industrial vibration and human-body motion, yet most of this energy remains underutilized. Piezocatalysis, piezo-photocatalysis and piezoelectric nanogenerators (PENGs) provide feasible routes to convert ambient mechanical-vibration energy into chemical energy and usable electricity. Distinct from conventional inorganic piezoelectric materials suffering from low specific surface area and limited structural tunability, covalent organic frameworks (COFs) possess tailorable skeletons, high porosity, excellent chemical–thermal stability and modular symmetry-engineering capability. Non-centrosymmetric COFs with intrinsic piezoelectric responses can be realized via rational monomer-level design. Nevertheless, research on piezoelectric-related COFs-based systems is still in its early exploratory stage, and comprehensive reviews covering piezocatalysis, piezo-photocatalysis and piezoelectric energy harvesting remain scarce. This review addresses both intrinsic piezoelectric COFs and COFs-containing hybrid composite systems. Notably, performance gains in composite systems cannot be simply attributed to the intrinsic piezoelectric response of the COFs component. We systematically discuss their fundamental mechanisms, unique flexible-pore electromechanical features, multi-scale modification strategies, diverse application scenarios, and unresolved challenges. We discuss the applicability and inherent limitations of core piezocatalytic interpretive frameworks for flexible porous COFs systems. Five mainstream strategies for boosting COF piezoresponse are summarized: building-block molecular design, defect engineering, morphology modulation, single-atom metal anchoring and heterostructure construction. Representative applications including water-energy conversion, CO2 reduction, organic-pollutant remediation, uranium (VI) reduction, antibacterial disinfection and mechanical-energy harvesting are presented. Key bottlenecks covering mechanistic ambiguity, characterization constraints, synthetic hurdles and long-term practical stability are highlighted, and targeted future research directions are proposed. This review offers instructive guidelines for developing high-performance symmetry-engineered COFs-based piezofunctional systems.

Nanomaterials doi: 10.3390/nano16211349

Authors: Tuğba Göcen Sevgi Haman Bayarı

Endohedral nitrogen fullerenes are promising candidates for molecular spin qubits and quantum sensing. We compare nitrogen spin localization and N···C contact topology in N@C60 and N@C70. Baseline structural, vibrational, electronic, population, spin density, noncovalent interaction (NCI), and quantum theory of atoms in molecules (QTAIM) analyses used UB3LYP/6-31G(d). Counterpoise-corrected interaction energies were calculated using UB3LYP-D3(BJ)/def2-TZVP, with def2-QZVP checks. QTAIM sensitivity was assessed at fixed geometries using UB3LYP/def2-TZVP and UωB97X-D/def2-TZVP. Encapsulation leaves both cages essentially unperturbed: selected vibrational shifts are ≤0.8 cm−1 and HOMO–LUMO gap changes are ≤0.007 eV. Frontier orbitals remain cage-dominated, whereas Mulliken and Hirshfeld analyses assign 94–99% of the spin population to nitrogen, without substantial charge transfer. Counterpoise-corrected def2-TZVP interaction energies are −9.09 and −8.55 kcal mol−1, respectively; def2-QZVP changes each by <0.05 kcal mol−1. NCI/QTAIM descriptors indicate weak, low-density N···C contacts. N@C60 retains 60 connections across all three tested levels; N@C70 has eight at baseline and the same six in both def2-TZVP calculations. Thus, extensive and restricted contact networks remain distinct, although the exact N@C70 count and local descriptors depend on computational level. Predominantly nitrogen-centered spin therefore accompanies different surrounding contact topologies in cages that differ in size and shape.

Nanomaterials doi: 10.3390/nano16211348

Authors: Zheng Qin Yongzhou Zhao Yutong Zhou Haihong Yu Yijun Zhang

Optical metamaterials provide a versatile platform for manipulating the amplitude, phase, and polarization of light at subwavelength scales and are therefore attractive for compact polarization-control devices. However, simultaneously realizing broadband polarization-selective absorption and transmission with bidirectional operation remains challenging. Here, we propose a bidirectional mid-infrared polarization-selective metamaterial comprising multilayer strip resonators integrated with a composite Au grating. For x-polarized incidence, the final bidirectional structure maintains an absorptance above 80% from 3.95 to 12.15 μm, with an average absorptance of 90.4%. For the orthogonal y-polarized incidence, the average transmittance reaches approximately 94% over the same spectral range. The device exhibits broadband polarization selectivity, with average absorption and transmission extinction ratios of 16.5 dB and 42.6 dB, respectively. Electromagnetic-field and structural analyses indicate that the broadband x-polarized absorption is associated with multiple localized resonances together with lattice- and Fabry–Pérot-cavity-related contributions, whereas the high y-polarized transmission is primarily enabled by the polarization-selective response of the Au grating. The symmetric configuration preserves these complementary polarization responses for illumination from either side, providing a route toward broadband multifunctional polarization control in the mid-infrared.

Nanomaterials doi: 10.3390/nano16211347

Authors: Bartłomiej Dominiak Julita Rosowska Agnieszka Wal Alicja Majewska Lena M. Rudy Bartłomiej S. Witkowski Łukasz Wachnicki Jarosław Kaszewski Anna Słońska Joanna Cymerys Mikołaj A. Gralak Marek Godlewski Michał M. Godlewski

With the growing use of nanotechnology, the issue of exposure to non-biodegradable nanomaterials is becoming increasingly significant, raising concerns about their potential impact on developing organisms. Their use in dentistry, optoelectronics and biomedicine leads to environmental exposure. Zirconium oxide (ZrO2) and yttrium oxide (Y2O3) nanoparticles are chemically stable and poorly soluble materials; however, their embryotoxicity remains extremely poorly characterised. This study assessed the effect of ZrO2 and Y2O3 nanoparticles on the development of chicken embryos. The nanoparticles were administered into the air chamber of the egg on the first day of incubation at concentrations of 10 and 100 µg/mL. The redox status was assessed based on superoxide dismutase activity, malondialdehyde content and the level of carbonylated proteins. Transcriptomic responses were evaluated using a whole-genome microarray, and selected genes were verified by qPCR. Both types of nanoparticles induced time-dependent changes in markers of oxidative stress. Transcriptomic analysis revealed distinctly different responses, with seven genes showing altered expression following ZrO2 administration, compared with 555 following Y2O3 administration. These results indicate that non-biodegradable metal oxide nanoparticles can influence the redox balance and gene expression during early embryonic development, with the extent of the response depending on the type of nanoparticle.

Nanomaterials doi: 10.3390/nano16211345

Authors: Susanne Bremer-Hoffmann Agnieszka Mech Hubert Rauscher

Overcoming the translational gap and accelerating the development of advanced materials require enabling tools that provide reliable information to support decision-making throughout the innovation process. New Approach Methodologies (NAMs) can contribute substantially by generating relevant information while reducing reliance on conventional testing approaches. However, the reliability and relevance of many NAMs have not yet been sufficiently established across the applicability domains relevant to advanced materials. Given their diversity and complexity, formal validation of NAMs across the entire range of materials and applications is unlikely to be realistic. Instead, a fit-for-purpose approach is needed, with the level of evidence and qualification tailored to the intended use and applicability domain of the NAM. During early innovation, NAMs may support exploration, research, and iterative decision-making, where full regulatory qualification may not be necessary. In contrast, NAMs used to support regulatory decisions require more stringent qualification. This perspective paper describes the different roles NAMs can play in innovation and discusses a flexible application of existing qualification criteria according to intended use, supporting efficient and accelerated innovation especially for advanced and complex materials while maintaining confidence in NAM-derived information.

Nanomaterials doi: 10.3390/nano16211346

Authors: Jiawei Chen Zean Yang Zhihao Zhao Wenyuan Zhang

Lithium-rich layered oxides (LLOs) constitute promising cathode candidates for next-generation Li-ion batteries, since their high reversible capacities arise from the combined contribution of transition-metal cations and lattice oxygen redox. However, their practical application is hampered by structural degradation arising from metastable anionic redox. Herein, a synergistic La/F co-doping strategy is reported by us so that the structural and electrochemical stability of LLOs can be enhanced. The complementary effects of La and F co-doping modification and their influence on crystal structure, elemental distribution, and electrochemical performance are systematically investigated. We demonstrate that La/F co-doping stabilizes the oxygen lattice framework, suppresses transition-metal migration into lithium layers, and promotes long-range structural ordering. Mechanistically, La3+ doping enlarges the lattice spacing to facilitate Li+ diffusion, while F− substitution strengthens metal–fluorine bonds, reinforcing the anionic framework and suppressing irreversible oxygen release. As a result, the La/F co-doped material (LMCNOLF) exhibits markedly improved initial Coulombic efficiency, superior rate capability, and excellent long-term cycling stability. Moreover, it retains 89% of its initial capacity after 300 cycles and outperforms both the La-doped and undoped counterparts. Kinetic analysis reveals that LMCNOLF maintains lower charge-transfer impedance and higher Li+ diffusion coefficients. This work elucidates the mechanism of La/F synergistic doping in stabilizing lattice oxygen and suppressing structural degradation, offering a rational design route for high-performance Li-rich layered cathodes.

Nanomaterials doi: 10.3390/nano16211344

Authors: Yuseong Kim Byoung-Nam Park

Building on a previously established metal–organic framework (MOF)-inspired deca-nary high-entropy oxide anode/alternating current electrophoretic deposition (AC-EPD) platform, this study elucidates the multication distribution, charge-storage kinetics, and long-term cycling advantage of a binder- and conductive-agent-free deca-nary high-entropy anode. The active material was synthesized using a metal–organic framework 74 (MOF-74)-inspired deca-metal solvothermal coordination approach. Although the product evolved into a crystalline multi-metal oxide derivative rather than retaining the MOF-74 topology, energy-dispersive X-ray spectroscopy (EDS) confirmed the atomic-level homogeneous distribution of ten distinct cations (Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Zn, Cd). The additive-free AC-EPD approach maximized the active material density and demonstrated the intrinsic electrochemical robustness of the high-entropy structure. Consequently, the electrode exhibited exceptional reversibility and superior rate capability (recovering ~310 mAh g−1 after 5.0 C cycling). Kinetic analysis revealed a dominant pseudocapacitive contribution (87% capacitive at 1.0 mV s−1), facilitating rapid lithium-ion transport. This work highlights a synergistic strategy combining MOF-inspired synthesis and electrophoretic fabrication for advanced high-entropy electrodes.

Nanomaterials doi: 10.3390/nano16211343

Authors: Bu-Hyun Moon Eo Jin Oh Hea Jung Park Dong-Soo Shin

Polyhedral oligomeric silsesquioxane (POSS) and double-decker silsesquioxane (DDSQ) are organic–inorganic hybrid nanostructures with well-defined siloxane frameworks that can be functionalized with various organic groups. In this study, a systematic series of six functional silsesquioxane derivatives was prepared using three different molecular architectures, POSS-8, DDSQ-4, and DDSQ-2. Three methacrylate-functionalized derivatives and three trimethoxysilane-functionalized derivatives were prepared from the corresponding Si–H-containing POSS and DDSQ precursors through hydrosilylation reactions. The target compounds were obtained in good yields of 81–91%, and their molecular structures were characterized by FT-IR, 1H and 13C NMR, 29Si NMR, and MALDI-TOF mass spectrometry. The spectroscopic results confirmed the successful introduction of the methacrylate and trimethoxysilane groups while maintaining the characteristic silsesquioxane frameworks. The parallel functionalization of POSS-8, DDSQ-4, and DDSQ-2 established a systematic series of silsesquioxane molecular precursors differing in framework architecture and peripheral functional-group density. The resulting derivatives contain either methacrylate or trimethoxysilane functionalities; however, their subsequent polymerization, hydrolysis/condensation, and material performance were not evaluated in the present study. Accordingly, these compounds are regarded as potential molecular precursors for further investigation.

Nanomaterials doi: 10.3390/nano16211342

Authors: Inês Côrte-Real Driss Belayach Ricardo Martuci João Sampaio-Fernandes Maria Helena Figueiral

Graphene-based materials, including graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoplatelets (GNPs), exhibit a relatively large surface area and tunable surface chemistry, enabling diverse biological interactions. These interactions depend on oxygen-containing functional groups, oxidation degree, lateral size, and surface charge. In dental materials, these properties support incorporation of graphene-based materials into polymer matrices to reduce microbial adhesion, inhibit biofilm formation, and limit infection-related degradation. This review critically evaluates GO, rGO, and GNPs in polymer-based dental materials, focusing on structure–property–biological response relationships and antimicrobial performance. Current evidence indicates that GO demonstrates the most consistent antibacterial and antifungal activity, mainly due to its high density of functional groups and hydrophilicity. In contrast, rGO and GNPs show more variable or moderate antimicrobial effects, often requiring surface modification, optimized composite design, or higher material loading. Here, key limitations affecting clinical application are also discussed. Several biological effects are concentration-dependent, including human cytotoxicity, host enzyme interactions, potential immune responses, long-term biocompatibility, and stability under oral conditions. By integrating mechanistic insights across graphene-based materials, this review clarifies their potential and current limitations for polymeric dental applications and identifies priorities supporting the transition from laboratory-scale research to clinical and industrial implementation strategies.