Search Results (1,109)

Background: Minimally invasive hyperthermia and regenerative therapies require materials that deliver precise, localized heat without compromising biocompatibility. Most conventional polymers are thermally insulating and challenging to control in vivo, motivating this review. Objectives: We aimed to (i) examine the use of thermally enhanced biopolymers in hyperthermia-based therapies, (ii) appraise evidence from clinical and preclinical studies, (iii) identify and classify principal applications in regenerative medicine. Methods: A PRISMA-guided systematic review (2020–2025) with predefined inclusion/exclusion criteria was conducted and complemented by a bibliometric analysis using VOSviewer for mapping and visualization. Results: Modifying biopolymers—via functionalization with photothermal or magnetic nanoagents (Au; Fe₂O₃/Fe₃O₄/CoFe₂O₄; CuS; Ag; MXenes, e.g., Nb₂C), crosslinking strategies, and hybrid formulations—significantly increased thermal conductivity, enabling localized hyperthermia and controlled drug release. In vitro and in vivo studies showed that europium-doped iron oxide nanoparticles embedded in chitosan generated heat efficiently while sparing healthy tissues, underscoring the need to balance biocompatibility and thermal performance. Hydrogel systems enriched with carbon nanomaterials (graphene, carbon nanotubes) and matrices such as GelMA, PNIPAM, hyaluronic acid, and PLA/PLGA demonstrated tissue compatibility and effective thermal behavior; graphene was compatible with neural tissue without inducing inflammation. Conclusions: Thermally conductive biopolymers show growing potential for oncology and regenerative medicine. The evidence supports further academic and interdisciplinary research to optimize safety, performance, and translational pathways. Full article

The photocatalytic degradation of Crystal Violet (CV) using ZnO-based nanomaterials presents a promising solution for addressing water pollution caused by synthetic dyes. This review highlights the exceptional efficiency of ZnO and its modified forms—such as doped, composite, and heterostructured variants—in degrading CV under both ultraviolet (UV) and solar irradiation. Key advancements include strategic bandgap engineering through doping (e.g., Cd, Mn, Co), innovative heterojunction designs (e.g., n-ZnO/p-Cu₂O, g-C₃N₄/ZnO), and composite formations with graphene oxide, which collectively enhance visible-light absorption and minimize charge recombination. The degradation mechanism, primarily driven by hydroxyl and superoxide radicals, leads to the complete mineralization of CV into non-toxic byproducts. Furthermore, this review emphasizes the emerging role of Artificial Neural Networks (ANNs) as superior tools for optimizing degradation parameters, demonstrating higher predictive accuracy and scalability compared to traditional methods like Response Surface Methodology (RSM). Potential operational challenges and future directions—including machine learning-driven optimization, real-effluent testing potential, and the development of solar-active catalysts—are further discussed. This work not only consolidates recent breakthroughs in ZnO-based photocatalysis but also provides a forward-looking perspective on sustainable wastewater treatment strategies. Full article

The truncated octagonal cuprous oxide photocatalysts were synthesized in the presence of polyvinylpyrrolidone. Zn-doped Cu₂O photocatalysts were successfully synthesized with different ZnSO₄/CuSO₄ ratios. The effects of Zn doping on the light absorption, morphology, separation of photogenerated charge carriers, and hydrogen production performance of the photocatalyst were investigated. The size and morphology of the Zn-doped Cu₂O-based nanomaterials change with increasing dosages of zinc sulfate dopant. Zn doping resulted in a reduction in crystallite size, a change in morphology, and a decrease in the size of the nanomaterial. The hydrogen production activity of the Zn-Cu₂O photocatalyst Zn-Cu₂O-2 with optimized dopant content can reach 9690 μmol h⁻¹g⁻¹. The enhanced photocatalytic activity of Zn-doped Cu₂O photocatalyst is achieved through significantly improved electron-hole separation, which is maximized at an optimal Zn dopant concentration. Full article

In this study, pure myristic acid (MA) polycrystals and those doped with Co and Cu were synthesized and characterized to evaluate their structural features, thermal properties, and antimicrobial effects against the bacterium Xanthomonas citri. Scanning electron microscopy revealed that doping with Co and Cu altered the crystal surfaces. Specifically, pure MA polycrystals exhibited rougher and more porous surfaces, whereas Co and Cu doped MA polycrystals displayed more compact and less porous morphologies. Energy-dispersive X-ray spectroscopy confirmed the presence of Co and Cu in the samples. X-ray diffraction indicated that all samples crystallized in the same monoclinic structure; however, Co and Cu doping led to a slight decrease in unit cell volume and average crystallite size. Raman spectroscopy revealed changes in the vibrational bands of the crystalline lattice. Thermal analyses demonstrated that the addition of Co and Cu ions influenced the thermal stability of pure MA. In microbiological assays, all samples exhibited antimicrobial activity against X. citri. In particular, Co-doped MA polycrystals showed bactericidal properties at all tested concentrations, while pure MA polycrystals exhibited bacteriostatic action at lower concentrations (≤15.6 µg/mL) and bactericidal action at higher concentrations. Cu-doped MA polycrystals did not inhibit bacterial growth at lower concentrations (7.8 µg/mL) but were bactericidal at higher concentrations. These results demonstrated increased lethality against X. citri, particularly for Co-doped MA polycrystals, which exhibited the lowest LD₅₀ value (the toxicological dose required to inhibit 50% of the tested population). Overall, these findings indicate that metal-doped MA polycrystals may be effective for future antimicrobial applications. Full article

In response to the rising global energy dilemma and associated environmental concerns, research into creating less hazardous solar technology has exploded. Due to their cost-effective fabrication process and exceptional optoelectronic properties, perovskite-based solar cells have emerged as promising candidates. However, their commercialization faces obstacles, including lead contamination, interface recombination, and instability. This study examines CaV_0.5Fe_0.5O₃ (CVFO) as an alternative to lead-based perovskites, highlighting its improved stability and high efficiency through a series of simulation and modeling results. A record power conversion efficiency (PCE) of 23.28% was achieved (V_oc = 1.38 V, J_sc = 19.8 mA/cm², FF = 85.2%) using a 550 nm thick CaV_0.5Fe_0.5O₃ as an absorber. This was accomplished by optimizing the electron transport layer (ETL: TiO₂, 40 nm, 10²⁰ cm⁻³ doping) and the hole transport layer (HTL: Cu₂O, 50 nm, 10²⁰ cm⁻³ doping). Subsequently, it was established that defects at the ETL/perovskite interface significantly diminish performance relative to defects on the HTL side, and thermal stability assessments verified proper operation up to 350 K. To maintain efficiency, it is necessary to reduce series resistance (R_s < 1 Ω·cm²) and increase shunt resistance (R_sh > 10⁴ Ω·cm²). The findings indicate that CaV_0.5Fe_0.5O₃ serves as a feasible alternative to perovskites and has the potential to enhance the performance of scalable solar cells. Full article

Cuprate delafossite phases such as CuMnO₂ (crednerite) and CuFeO₂, as well as iron- and manganese-doped mcconnellite composites, were investigated as candidates for producing intense black ceramic pigments via conventional solid-state synthesis. Both electric kiln and fast dielectric (microwave) firing methods were employed, with mcconnellite (CuCrO₂) used as a reference pigment. Microwave firing led to a marked improvement in sample blackness compared to conventional electric firing. Among the delafossite phases, only mcconnellite subjected to microwave-assisted firing (R_Vis = 1.40%, corresponding to 98.60% visible light absorption) emerges, pending further optimization, as a promising candidate for an ultra-black ceramic pigment (R_Vis < 1%) under optimized glaze conditions (ZnO-free) and a firing temperature of 1000 °C. Considering the pigments in powder form, microwave-fired crednerite (R_Vis = 4.85%, 95.15% absorption) and iron- and iron–manganese-doped mcconnellite composites (R_Vis = 3.27% and 3.23%, respectively) appear as potential candidates for deep-black pigments (R_Vis < 3%), benefiting from the composite effect between the delafossite phase and the associated chromium spinel. Moreover, microwave-fired crednerite also demonstrates noteworthy potential for deep-black coloration in glazed samples (R_Vis = 4.27%, 95.73% absorption). Full article

In this study, p-type NiO_x and Cu-doped NiO_x nanoparticles (NPs) were synthesized by a simple chemical precipitation method and used as hole transport layers (HTLs) for inverted perovskite solar cells (PSCs). The microstructural property, surface morphology, elemental composition, optical property, charge recombination, and surface topography of the NiO_x and Cu-NiO_x HTLs were comprehensively characterized. The results showed that the NiO_x and Cu-NiO_x NPs were uniformly coated on the substrates without pinholes or voids. Cu incorporation into NiO_x did not change its crystalline nature and considerably improved its electrical conductivity. The Cu-NiO_x HTLs exhibited superior photoluminescence quenching and the least lifetime decay, which indicated that Cu-NiO_x exhibited higher charge transport than NiO_x HTLs. The fabricated PSC performances were further analyzed using current density–voltage characteristics, external quantum efficiency, and electrochemical impedance spectroscopy. The PSCs with PEDOT:PSS, NiO_x, and 2% Cu-NiO_x HTLs exhibited power conversion efficiencies of 11.93%, 13.72%, and 15.54%, respectively. The 2% Cu-NiO_x HTL-based device showed the best performance compared with the PEDOT:PSS- and NiO_x-based devices. Academic Editors: Chunyang Zhang, Dou Zhang Full article

Cu₂O solar cells are regarded as a promising emerging inorganic photovoltaic technology due to their power conversion efficiency (PCE) potential and material sustainability. While previous studies primarily focused on the band offset between n-type buffer layers and Cu₂O optical absorption, this work systematically investigated an ETL/buffer/p-Cu₂O/HTL heterojunction structure using SCAPS-1D simulations. Key design parameters, including bandgap (Eg) and electron affinity (χ) matching across layers, were optimized to minimize carrier transport barriers. Furthermore, the doping concentration and thickness of each functional layer (ETL: transparent conductive oxide; HTL: hole transport layer) were tailored to balance electron conductivity, parasitic absorption, and Auger recombination. Through this approach, a maximum PCE of 14.12% was achieved (V_oc = 1.51V, J_sc = 10.52 mA/cm², FF = 88.9%). The study also identified candidate materials for ETL (e.g., GaN, ZnO:Mg) and HTL (e.g., ZnTe, NiO_x), along with optimal thicknesses and doping ranges for the Cu₂O absorber. These findings provide critical guidance for advancing high-performance Cu₂O solar cells. Full article

Electrocatalytic conversion of CO₂ to high-energy-density multicarbon products (C₂₊) offers a sustainable route for renewable energy storage and carbon neutrality. Precisely modulating Cu-based catalysts to enhance C₂₊ selectivity remains challenging due to uncontrollable reduction of Cu^δ+ active sites. Here, an efficient and stable Ge/Cu catalyst was developed for CO₂ reduction to ethanol via Ge modification. A Cu₂O/GeO₂/Cu core–shell composite was constructed by controlling Ge doping. The structure–performance relationship was elucidated through in situ characterization and theoretical calculations. Ge⁴⁺ stabilized Cu¹⁺ active sites and regulated the surface microenvironment via electronic effects. Ge modification simultaneously altered CO intermediate adsorption to promote asymmetric CO–CHO coupling, optimized water structure at the electrode/electrolyte interface, and inhibited over-reduction of Cu^δ+. This multi-scale synergistic effect enabled a significant ethanol Faradaic efficiency enhancement (11–20%) over a wide potential range, demonstrating promising applicability for renewable energy conversion. This study provides a strategy for designing efficient ECR catalysts and offers mechanistic insights into interfacial engineering for C–C coupling in sustainable fuel production. Full article

Advancements in flexible, low-cost, and recyclable alternatives to transparent conductive oxides (TCOs) are critical challenges in the sustainability of third-generation solar cells. This work introduces a copper mesh-based transparent electrode for dye-sensitized solar cells, replacing conventional fluorine doped-tin oxide (FTO)-coated glass to simultaneously reduce spectral reflection losses, enhance mechanical flexibility, and enable material recyclability. Titanium dioxide (TiO₂) photoanodes were synthesized and directly deposited onto the mesh via a single-step, low-energy ball milling process, which eliminates TiO₂ paste preparation and high-temperature annealing while reducing fabrication time from over three hours to 30 min. Structural and surface analyses confirmed the deposition of high-purity anatase-phase TiO₂ with strong adhesion to the mesh branches, enabling improved dye loading and electron injection pathways. Optical studies revealed higher visible light absorption for the copper mesh compared to FTO in the visible range, further enhanced upon TiO₂ and Ru-based dye deposition. Electrochemical measurements showed that TiO₂/Cu mesh electrodes exhibited significantly higher photocurrent densities and faster photo response rates than bare Cu mesh, with dye-sensitized Cu mesh achieving the lowest charge transfer resistance in impedance analysis. Techno–economic and sustainability assessments revealed a decrease of 7.8% in cost and 82% in CO₂ emissions associated with the fabrication of electrodes as compared to conventional TCO electrodes. The synergy between high conductivity, transparency, mechanical durability, and a scalable, recyclable fabrication route positions this architecture as a strong candidate for next-generation dye-sensitized solar modules that are both flexible and sustainable. Full article

In the application of ceramic dielectric filters, to achieve electromagnetic shielding of signals and subsequent integrated applications, it is necessary to carry out metallization treatment on their surfaces. The quality of metallization directly affects the performance of the filter. However, when in use, the filter may encounter harsh environmental conditions. Therefore, the surface-metallized film needs to have strong corrosion resistance to ensure its long-term stability during use. In this paper, Cu films and copper–chromium alloy films were fabricated on Si (100) substrates and BaTiO₃ ceramic substrates by HiPIMS technology. The effects of different added amounts of Cr on the microstructure, electrical conductivity, and corrosion resistance of the Cu films were studied. The results show that with an increase in Cr content, the preferred orientation of the (111) crystal plane gradually weakens, and the grains of the Cu-Cr alloy film gradually decrease. The particles on the film surface are relatively coarse, increasing the surface roughness of the film. However, after doping, the film still maintains a relatively low surface roughness. After doping with Cr, the resistivity of the film increases with the increase in Cr content. The film–substrate bonding force shows a trend of first increasing and then decreasing with the increase in Cr content. Among them, when the Cr content is 2 at.%, the film–substrate bonding force is the greatest. The Cu-Cr alloy film has good corrosion resistance in static corrosion. With the increase in Cr content, the Tafel slope of the cathode increases, and the polarization resistance R_p also increases with the increase in Cr content. After the addition of Cr, both the oxide film resistance and the charge transfer resistance of the electrode reaction of the Cu-Cr alloy film are greater than those of the Cu film. This indicates that the addition of Cr reduces the corrosion rate of the alloy film and enhances its corrosion resistance in a NaCl solution. 2 at.% Cr represents a balanced trade-off in composition. While ensuring the film is dense, uniform, and has good electrical conductivity, the adhesion between the film and the substrate is maximized, and the corrosion resistance of the Cu film is also improved. Full article

Zinc oxide (ZnO) nanomaterials have emerged as promising candidates for gas sensing applications due to their high sensitivity, fast response–recovery cycles, thermal and chemical stability, and low fabrication cost. However, the performance of pristine ZnO remains limited by high operating temperatures, poor selectivity, and suboptimal detection at low gas concentrations. To address these limitations, significant research efforts have focused on dopant incorporation and polymer hybridization. This review summarizes recent advances in dopant engineering using elements such as Al, Ga, Mg, In, Sn, and transition metals (Co, Ni, Cu), which modulate ZnO’s crystal structure, defect density, carrier concentration, and surface activity—resulting in enhanced gas adsorption and electron transport. Furthermore, ZnO–polymer nanocomposites (e.g., with polyaniline, polypyrrole, PEG, and chitosan) exhibit improved flexibility, surface functionality, and room-temperature responsiveness due to the presence of active functional groups and tunable porosity. The synergistic combination of dopants and polymers facilitates enhanced charge transfer, increased surface area, and stronger gas–molecule interactions. Where applicable, sol–gel-based studies are explicitly highlighted and contrasted with non-sol–gel routes to show how synthesis controls defect chemistry, morphology, and sensing metrics. This review provides a comprehensive understanding of the structure–function relationships in doped ZnO and ZnO–polymer hybrids and offers guidelines for the rational design of next-generation, low-power, and selective gas sensors for environmental and industrial applications. Full article

In this study, wastewater generated from tilapia biofloc aquaculture was treated using the electro-oxidation (EO) process in a batch reactor. Optimal reaction conditions were determined through a robust screening design based on a Taguchi L₉ (3⁴) orthogonal array. The evaluated parameters included three anode–cathode configurations—boron-doped diamond with titanium (BDD–Ti), BDD with copper (BDD–Cu), and BDD with BDD—as well as current intensity (1–2 A), initial pH (5.5–11.5), and treatment time (2.5–3.5 h). The EO process exhibited high removal efficiencies for key water quality indicators. Under optimal conditions (BDD–Ti, i = 2 A, t = 3.5 h, pH₀ = 11.5), removal efficiencies of 96.57% for chemical oxygen demand (COD), 99.06% for total ammoniacal nitrogen (TAN), 67.68% for turbidity, and 81.09% for total organic carbon (TOC) were obtained. Phytotoxicity and bioassay tests further confirmed the detoxification potential of the treated effluent. Overall, the proposed green treatment approach demonstrates that EO is a viable and sustainable strategy for improving effluent quality and advancing water management in intensive aquaculture systems. Full article

Generally, atomic doping is an effective method to address the weak bonding strength of the graphene/aluminum (Gr/Al) composite interface structure caused by physical adsorption, thereby enhancing the mechanical properties of the interface structure. In this paper, the nanoscopic influence mechanisms of atomic (M, including 12 types of atoms (elements)) doping in the aluminum matrix (Al) on the ideal strength of the Gr/Al interface structures are investigated based on density functional theory. The analysis of the electronic properties of the typical interface structures reveals that doping with scandium (Sc), copper (Cu) and manganese (Mn) atoms can all improve the interface binding energy of the Gr/Al structures, but their effects on the ideal strength are different. Sc doping disrupts the symmetry of the graphene structure so as to enhance the interface binding energy, but the ideal strength of the Gr/Al structures is decreased. For Cu doping it shows good compatibility with the Al matrix and the interface binding energy is enhanced through Cu alloying with the Al matrix, while the ideal strength of the interface remains basically unchanged. As for Mn doping, it causes the charge to accumulate around the Mn atoms and a resonance peak between the d_Z² orbitals of Mn and the p_x orbitals of Al to form, thereby improving the ideal strength of the interface structure. This study provides valuable insights for the design of Gr/Al composites by elucidating the underlying mechanisms for enhancing interface mechanical properties. Full article

In this study, barium-doped lanthanum copper oxide (LaCuO) thin films were deposited onto quartz glass substrates using a radio frequency (RF) magnetron sputtering system. The deposited films were subsequently subjected to a selenization annealing process to convert them into barium-doped lanthanum copper oxyselenide (LaCuOSe:Ba) thin films. Selenization was conducted at annealing temperatures of 750 °C, 800 °C, 850 °C, and 900 °C to determine the optimal processing conditions for achieving high-quality LaCuOSe:Ba films. Structural and compositional analyses were performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results indicated that the primary phase of the films under all conditions was LaCuOSe. However, at annealing temperatures above 850 °C, secondary phases, such as Cu₂Se and La₂O₂Se, were formed, indicating partial decomposition or phase separation at elevated temperatures. Among the conditions tested, the film annealed at 850 °C exhibited the most favorable optoelectronic properties. It demonstrated an average visible light transmittance of 59%, an electrical resistivity of 6.37 × 10⁻³ Ω·cm, a carrier mobility of 5.87 cm²/V·s, and a carrier concentration of 2.15 × 10²⁰ cm⁻³. These values yielded the highest calculated figure of merit for transparent conducting films, reaching 1.6 × 10⁻⁵ Ω⁻¹, signifying an optimal balance between transparency and conductivity under these processing conditions. Full article