Search Results (3,229)

This research explores the effect of a composite support of SiO₂ and Al₂O₃ with Fe and Co incorporated as catalysts for Fischer–Tropsch synthesis (FTS) using a 3D-printed stainless steel (SS) microchannel microreactor. Two mesoporous catalysts, FeCo/SiO₂Al₂O₃ and Co/SiO₂Al₂O₃, were synthesized via a one-pot (OP) method and extensively characterized using N₂ physisorption, XRD, SEM, TEM, H₂-TPR, TGA-DSC, FTIR, and XPS. H₂-TPR results revealed that the synthesis method significantly affected the reducibility of metal oxides, thereby influencing the formation of active FTS sites. SEM-EDS and TEM further revealed a well-defined hexagonal matrix with a porous surface morphology and uniform metal ion distribution. FTS reactions, carried out in the 200–350 °C temperature range at 20 bar with a H₂/CO molar ratio of 2:1, exhibited the highest activity for FeCo/SiO₂Al₂O₃, with up to 80% CO conversion. Long-term stability was evaluated by monitoring the catalyst performance for 30 h on stream at 320 °C under identical reaction conditions. The catalyst was initially active for the methanation reaction for up to 15 h, after which the selectivity for CH₄ declined. Correspondingly, the C₄⁺ selectivity increased after 15 h of time-on-stream, indicating a shift in the product distribution toward longer-chain hydrocarbons. This trend suggests that the catalyst undergoes gradual activation or restructuring under reaction conditions, which enhances chain growth over time. The increase in C₄⁺ products may be attributed to the stabilization of the active sites and suppression of methane or light hydrocarbon formation. Full article

The presence of various Ag species (Ag⁺ ions, Ag clusters, and Ag nanoparticles (NPs)) in Ag-zeolite nanocomposites strongly influences their catalytic, photocatalytic, and antibacterial properties. To tailor materials for specific applications, it is essential to employ strategies that control the redox processes between Ag⁺ and Ag⁰ and facilitate the formation of active Ag-containing composites. In this study, we present a comparative analysis of Ag-zeolite nanocomposites, focusing on their synthesis methods, structural characteristics, and antibacterial activity against Escherichia coli. Ag NPs were synthesized using three approaches: solid-state thermal reduction, chemical reduction in aqueous solutions with a mild reducing agent (sodium citrate, Na₃Cit), and chemical reduction with a strong reducing agent (sodium borohydride, NaBH₄). The resulting materials were characterized by X-ray diffraction (XRD), diffuse reflectance UV–Vis spectroscopy (DR UV–Vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), while antibacterial activity was assessed using biological assays. Microscopic and spectroscopic analyses confirmed the formation of Ag NPs and the co-existence of immobilized Ag⁺ ions within the zeolite framework. The specific influence of the treatment method of Ag⁺-zeolite on the presence of silver species in the nanocomposites and their role in antibacterial properties were evaluated. The highest antibacterial efficiency was observed in the nanocomposite produced by thermal treatment of Ag-exchanged zeolite. Thus, the crucial function of Ag⁺ ions in the mechanism of bacteria cell death was suggested. Full article

Lanthanide/transition metal-doped luminescent materials are advanced materials with broad application potential. This type of material achieves control and optimization of luminescence performance by introducing lanthanide/transition metal ions into the host material and utilizing its unique electronic structure and optical properties. Luminescent materials are suitable for optical communication devices, biological imaging, and photodetectors. The combination of lanthanide/transition metals with various matrix materials provides a new platform for creating new chemical and physical properties in materials science and device applications. In this paper, we summarize the latest progress in the research of lanthanide/transition metal-doped luminescent materials and explain their roles in biological imaging, sensing, and optoelectronic applications. It starts with various synthesis techniques and explores how to cleverly incorporate rare earth/transition metals into various matrices, thereby endowing them with unique properties. Then, the advantages and disadvantages of each synthesis technique are discussed. Subsequently, the focus will be on functional strategies and their applications. Finally, strategies for lanthanide/transition metal ion-doped luminescent materials to address challenges are proposed, and insights from each section are summarized. Full article

Tryptophan hydroxylase 2 (TPH2) hydroxylates L-tryptophan to L-5-hydroxytryptophan (5-HTP) the first and rate-limiting step of serotonin (5-HT) synthesis in the mammalian brain. Some mutations in the Tph2 gene reducing TPH2 activity are associated with hereditary depressive disorders. The P447R substitution in the mouse TPH2 molecule reduces its thermal stability in vitro and its activity in the brain. The effects of iron ions on thermal stability in vitro and the activity in the brain of the mutant TPH2 were investigated. In the in vitro experiment effects of 0.01, 0.05, and 0.2 mM of FeSO₄ and FeCl₃ on the enthalpy (ΔH) and Gibbs free energy (ΔG) of thermal denaturation of the mutant TPH2 extracted from the midbrain of Balb/c mice were assayed. All FeSO₄ concentrations and 0.05 and 0.2 mM concentrations of FeCl₃ increased these thermodynamic characteristics of the mutant TPH2. Repeated (for 7 days) intramuscular administration of Fe(III) hydroxide dextran complex (15 and 30 mg/kg/day) increased TPH2 activity in the hippocampus, but not in the midbrain in Balb/c mice. Repeated (for 7 days) intramuscular administration of Fe(III) hydroxide dextran complex (15 and 30 mg/kg/day) together with thiamine (8 mg/kg/day) and cyanocobalamin (0.8 mg/kg/day) increased TPH2 activity in the hippocampus, while 30 mg/kg of Fe(III) hydroxide dextran also increased the enzyme activity in the midbrain in Balb/c mice. These results are the first evidence for chaperone-like effects of iron ions on thermal stability in vitro and activity in the brain of the mutant TPH2. Full article

Against the backdrop of accelerating global energy transition, developing high-performance energy-storage systems is crucial for achieving carbon neutrality. Traditional electrode materials are limited by a single densification storage mechanism and low conductivity, struggling to meet demands for high energy/power density and a long cycle life. Carbon/high-entropy alloy nanocomposites provide an innovative solution through multi-component synergistic effects and cross-scale structural design: the “cocktail effect” of high-entropy alloys confers excellent redox activity and structural stability, while the three-dimensional conductive network of the carbon skeleton enhances charge transfer efficiency. Together, they achieve synergistic enhancement via interfacial electron coupling, stress buffering, and dual storage mechanisms. This review systematically analyzes the charge storage/attenuation mechanisms and performance advantages of this composite material in diverse energy-storage devices (lithium-ion batteries, lithium-sulfur batteries, etc.), evaluates the characteristics and limitations of preparation techniques such as mechanical alloying and chemical vapor deposition, identifies five major challenges (including complex and costly synthesis, ambiguous interfacial interaction mechanisms, lagging theoretical research, performance-cost trade-offs, and slow industrialization processes), and prospectively proposes eight research directions (including multi-scale structural regulation and sustainable preparation technologies, etc.). Through interdisciplinary perspectives, this review aims to provide a theoretical foundation for deepening the understanding of carbon/high-entropy alloy composite energy-storage mechanisms and guiding industrial applications, thereby advancing breakthroughs in electrochemical energy-storage technology under the energy transition. Full article

Despite notable advancements in lithium-ion battery (LIB) technology, growing industrialization, rising energy demands, and evolving consumer electronics continue to raise performance requirements. As the primary determinant of battery performance, cathode materials have become a central research focus. Among emerging candidates, iron-based fluorides show great promise due to their high theoretical specific capacities, elevated operating voltages, low cost (owing to abundant iron and fluorine), and structurally diverse crystalline forms such as pyrochlore and tungsten bronze types. These features make them strong contenders for next-generation high-energy, low-cost LIBs. This review highlights recent progress in iron-based fluoride cathode materials, with an emphasis on structural regulation and performance enhancement strategies. Using pyrochlore-type hydrated iron trifluoride (Fe₂F₅·H₂O), synthesized via ionic liquids like BmimBF₄, as a representative example, we discuss key methods for tuning physicochemical properties—such as electronic conductivity, ion diffusion, and structural stability—via doping, compositing, nanostructuring, and surface engineering. Advanced characterization tools (XRD, SEM/TEM, XPS, Raman, synchrotron radiation) and electrochemical analyses are used to reveal structure–property–performance relationships. Finally, we explore current challenges and future directions to guide the practical deployment of iron-based fluorides in LIBs. This review provides theoretical insights for designing high-performance, cost-effective cathode materials. Full article

In this work, (NaBi)_0.5−x(LiSm)_xBi₂Nb₂O₉ (NBN-xLS, x = 0.00–0.06) ceramics were fabricated by co-doping of LiSm into Na_0.5Bi_2.5Nb₂O₉. The traditional solid-phase technique was employed for the entire synthesis process. The impact of LiSm doping on the crystal structure, dielectric, ferroelectric, and piezoelectric properties, as well as the underlying conduction mechanisms in the NBN-xLS ceramics, was analyzed systematically. The XRD patterns and the Rietveld refinement revealed that lattice distortion reduced with an increase in the LiSm doping amount. The decrease in lattice distortion significantly contributed to its improved ferroelectric and piezoelectric characteristics. The results showed that the NBN-xLS ceramics were primarily p-type materials due to their bulk-limited conduction, with oxygen holes and vacancies acting as the conducting species, and the appearance of weak ion conduction at high temperatures. The NBN-0.04LS ceramic, in particular, displayed the highest performance, with P_r, T_c, and d₃₃ values of 9.05 μC/cm², 777 °C, and 25.2 pC/N, respectively. Additionally, the ceramic displayed remarkable thermal stability, with its d₃₃ retaining 95.0% of its original value after annealing at 760 °C. These results demonstrate that LiSm co-doped Na_0.5Bi_2.5Nb₂O₉ ceramics have potential for use in high-temperature sensors. Full article

Graphene nanoshells (MGNS) were prepared from cellulose, a sustainable biopolymer. Different sizes/morphologies were obtained by simply changing the metal catalyst salt in the synthesis. The MGNS were shown to reversibly cycle Li-ions by an intercalation mechanism similar to graphite. The reversible capacity of each MGNS prepared from different metal salts correlates well to its degree of 3-D graphitic order. The small size of the MGNS allows for short Li diffusion distances and very rapid charging, obtaining a 20% charge in 36 s (100 C rate). The unique spherical structure provides stable cycling, losing only 3.8% capacity over 900 cycles, and eliminates exfoliation that occurs when cycling graphite in propylene carbonate (PC), an inexpensive, environmentally friendly electrolyte. This enables cycling in a PC-only solvent-based electrolyte, with stable cycling and high capacities at temperatures as low as −35 °C. At this very low temperature, 95% of the RT reversible capacity is retained, with only a modest charge potential increase due to the increase in viscosity of the solvent. Full article

Rapid growth of electric vehicles has increased demand for lithium-ion batteries (LIBs), raising concerns regarding their end-of-life management. This study comprehensively evaluates the closed-loop recycling of cathode materials from spent LIBs by integrating life cycle assessment (LCA), technoeconomic analysis, and technological comparison. Typical approaches—including pyrometallurgy, hydrometallurgy, and other processes such as organic acid leaching and in situ reduction roasting—are systematically reviewed. While pyrometallurgy offers scalability, it is hindered by high energy consumption and excessive greenhouse gas emissions. Hydrometallurgy achieves higher metal recovery rates with better environmental performance but requires complex chemical and wastewater management. Emerging methods and regeneration techniques such as co-precipitation and sol–gel synthesis demonstrate potential for high-purity material recovery and circular manufacturing. LCA results confirm that recycling significantly reduces GHG emissions, especially for high-nickel cathode chemistry. However, the environmental benefits are affected by upstream factors such as collection, disassembly, and logistics. Technoeconomic simulations show that profitability is strongly influenced by battery composition, regional cost structures, and collection rates. The study highlights the necessity of harmonized LCA boundaries, process optimization, and supportive policy frameworks to scale environmentally and economically sustainable LIB recycling, ensuring long-term supply security for critical battery materials. Full article

The state of the art in the thermodynamics of calix[4]resorcinarene derivatives and its metal ion complexes is briefly discussed in the introduction. This is followed by the synthesis and characterization of a recyclable calix[4]resorcinarene amide derivative (L). The 1H NMR analyses in CD3CN and CD3OD showed solvent-dependent conformational changes with a notable downfield chemical shift in the aromatic proton (H-2) in moving from deuterated methanol to acetonitrile, indicating an interaction of the solvent within the ligand cavity as suggested by molecular dynamic simulations. 1H NMR complexation in acetonitrile revealed that L forms relatively strong 1:1 complexes with cations, with selectivity for Ca(II) and, to lesser extent, with Pb(II) over other metal cations. The composition of the complexes is corroborated by conductance measurements. The thermodynamics of these systems indicate that the complexation process is predominantly enthalpy controlled in acetonitrile, while it is entropy controlled in methanol. A remarkable outcome of fundamental studies is found in its application as new material for the removal of Ca(II) from water. The capacity of L to remove Ca(II) from water is 24 mmol/g which exceeds by far the capacity of cation exchange resins. Full article

Amid concurrent pressures on water and material resources, recovering valuable ions like lithium and nutrients from brines and wastewater is a critical tenet of the circular economy. This review provides a critical assessment of electro-driven membranes (EDMs) as a key technology platform for achieving this goal with high energy efficiency. A comprehensive synthesis and analysis of the current state-of-the-art of core EDM technologies, including electrodialysis (ED) and membrane capacitive deionization (MCDI), is presented, focusing the analysis on the performance metrics of specific energy consumption and ion selectivity. The findings reveal that the optimal EDM technology is highly application-dependent, with MCDI excelling for dilute streams and ED for concentrated ones. While significant advances in monovalent selective membranes have enabled lithium recovery, achieving high selectivity between ions of the same valence (e.g., Li⁺/Na⁺) remains a fundamental challenge. Moreover, persistent issues of membrane fouling and scaling continue to inflate energy consumption and represent a major bottleneck for industrial-scale deployment. While EDMs are a vital technology for ion resource recovery, unlocking their full potential requires a dual-pronged approach: advancing materials science to design novel, highly selective membranes, while simultaneously developing intelligently integrated systems to surmount existing performance and economic barriers. Full article

Industrial pollution caused by Cu(II) ions remains one of the most critical environmental challenges worldwide. A novel green-fluorescent aerogel has been successfully developed for simultaneous sensing and adsorption of Cu(II) through the cross-linking of carboxymethyl nanocellulose and carbon dots (C dots) using epichlorohydrin as a linker. The C dots were synthesized by heating glucose and aspartate mixed solutions at 150 °C. Under UV illumination, the aerogel exhibited intense homogeneous green fluorescence originating from the uniformly dispersed C dots, whose emission can be efficiently quenched by Cu(II) ions. By leveraging smartphone-based imaging, the concentration of Cu(II) was quantified within the range of 5–200 µg/L, with a detection limit of 3.7 µg/L. The adsorption isotherm of Cu(II) onto the aerogel strictly conformed to the Freundlich isotherm model (fitting coefficient R² = 0.9992), indicating a hybrid adsorption mechanism involving both physical adsorption and chemical complexation. The maximum adsorption capacity reached 149.62 mg/g, a value surpassing many reported adsorbents. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy analyses confirmed that the interactions between the aerogel and Cu(II) involved chelation and redox reactions, mediated by functional groups such as hydroxyl, amino, and carboxyl moieties. The straightforward fabrication process of the aerogel, coupled with its low cost, abundant raw materials, facile synthesis, and superior Cu(II) removal efficiency, positions this bifunctional fluorescent material as a promising candidate for large-scale environmental remediation applications. Full article

Soil salinity severely impairs plant growth, and polyamines such as spermidine (Spd) are known to bolster stress tolerance by acting as osmoprotectants and signaling molecules. Using TiO₂ enrichment, iTRAQ quantification, and bioinformatics analysis, we identified 870 proteins and 157 differentially phosphorylated proteins. Functional annotation showed that salt stress activated key components of the Salt Overly Sensitive pathway, particularly serine threonine kinases (SOS2) and Ca²⁺ binding sensors (SOS3). Among thirty-six SOS-associated kinases detected, eight SOS2 isoforms, four MAPKs, and two SOS3 homologs were significantly upregulated by NaCl, and Spd further increased the phosphorylation of six SOS2 proteins and one SOS3 protein under salt stress, with no detectable effect on SOS1. qRT PCR revealed enhanced expression of MAPKs and calcium-dependent protein kinases, suggesting a phosphorylation-centered model in which Spd amplifies Ca²⁺-mediated SOS signaling and reinforces ion homeostasis through coordinated transcriptional priming and post-translational control. Additional, proteins involved in protein synthesis and turnover (ribosomal subunits, translation initiation factors, ubiquitin–proteasome components), DNA replication and transcription, and RNA processing showed differential expression under salt or Spd treatment. Central metabolic pathways were reprogrammed, involving glycolysis, the TCA cycle, the pentose phosphate pathway, as well as ammonium transporters and amino acid biosynthetic enzymes. These findings indicate that exogenous Spd regulated phosphorylation-mediated networks involving the SOS signaling pathway, protein homeostasis, and metabolism, thereby enhancing cucumber salt tolerance. Full article

Mechanical forces shape immune responses in both health and disease. PIEZO1 and PIEZO2, two mechanosensitive ion channels, have emerged as critical transducers of these forces, influencing inflammation, pain, fibrosis, and neuroimmune regulation. This review aims to synthesize the current evidence on the role of PIEZO channels in mechano-inflammation, with a specific focus on their regulatory function in neuroimmune crosstalk. A comprehensive narrative synthesis was performed using the literature from PubMed, Scopus, and Web of Science up to June 2025. Experimental, translational, and mechanistic studies involving PIEZO channels in inflammatory, fibrotic, and neuroimmune processes were included. PIEZO1 is broadly expressed in immune cells, fibroblasts, and endothelial cells, where it regulates calcium-dependent activation of pro-inflammatory pathways, such as NF-kB and STAT1. PIEZO2, enriched in sensory neurons, contributes to mechanosensory amplification of inflammatory pain. Both channels are mechanistically involved in neuroinflammation, glial activation, blood–brain barrier dysfunction, connective tissue fibrosis, and visceral hypersensitivity. PIEZO channels act as integrators of biomechanical and immunological signaling. Their roles as context-dependent gatekeepers of neuroimmune crosstalk make them attractive targets for novel therapies. Full article

Due to its unique layered structure that facilitates ion intercalation and deintercalation, δ-MnO₂ has emerged as a promising cathode material for aqueous zinc-ion batteries (ZIBs). However, its structural collapse and Mn dissolution during prolonged cycling significantly limit its practical application. In this study, we demonstrate that metal ion doping, particularly with Fe³⁺, can effectively stabilize the δ-MnO₂ structure and enhance its electrochemical performance. Through a hydrothermal synthesis approach, δ-MnO₂ materials with varying Fe³⁺ doping ratios are prepared and systematically investigated. Among them, the sample with a Mn:Fe molar ratio of 20:1 exhibits the best performance, maintaining the layered δ-MnO₂ phase while significantly increasing Mn³⁺ content and promoting the formation of oxygen vacancies. At a current density of 0.5 A·g⁻¹, the iron-doped sample exhibited an initial specific capacity of 116.24 mAh·g⁻¹, with a capacity retention rate of 41.7% after 200 cycles. In contrast, the undoped δ-MnO₂ showed an initial specific capacity of only 85.15 mAh·g⁻¹, with a capacity retention rate of merely 19.9% after 200 cycles. The results suggest that Fe³⁺ doping not only suppresses Mn dissolution but also improves structural stability and Zn²⁺ transport kinetics. This work provides new insights into the development of durable Mn-based cathode materials for aqueous ZIBs. Full article