Journal of Materials Science最新文献

Accelerating global industrialization has led to energy shortages and environmental pollution, posing significant challenges to human society. Photocatalysis and piezoelectric catalysis, as green, low-energy-consumption catalytic technologies, demonstrate tremendous potential for achieving nitrogen reduction and pollutant degradation under mild conditions. This work successfully synthesized a V₆O₁₃/BiMOF/BiVO₄ composite catalyst using 1, 4-benzenedioic acid (H₂BDC) as a ligand and BiVO₄ as a bismuth source via a solvothermal method. The structural characteristics and performance of this catalyst in piezoelectric photocatalytic nitrogen fixation and methyl orange degradation were systematically investigated. Results indicate that the catalyst exhibits outstanding catalytic activity under visible light and ultrasonic irradiation, achieving a nitrogen fixation efficiency of up to 13.4 mmol L⁻¹ g⁻¹ h⁻¹ and a 94.5% degradation rate of methyl orange within 60 minutes, respectively. This work realizes simultaneous defect engineering and heterostructure construction via a one-step solvothermal strategy, forming a stable multifunctional composite interface. The piezoelectric polarization field can precisely control the charge transport pathways within Type I heterojunctions, transforming the conventional defects of such heterojunctions into catalytic advantages. This work provides a novel design approach and theoretical framework for the development of long-lasting, highly efficient piezoelectric photocatalytic materials for use in energy conversion and environmental remediation.

Graphical abstract

The limited capacity of electrode materials, along with limited potential windows, presents a constraint for improving energy density (E_d) and practical feasibility in asymmetric supercapacitors (ASCs). The phase composition, morphology, and electroanalytical characteristics of the PCN-777/Mo₂C@Fe₂O₃ electrodes were comprehensively evaluated. The results contributed to the development of a high-performance flexible ASC with an E_d of 79 Wh/kg at a power density (P_d) of 1450 W/kg, cycling stability, and an 88.9% capacity retention over 1000 cycles. The combined plan for the progress of practical energy storage technologies and the hydrogen evolution reaction (HER) for practical use offers basic visions for the creative design of electrode materials.

Graphical abstract

The PVDF-based polymer electrolyte has the disadvantages of low ionic conductivity and low Li⁺ migration number at room temperature, which hinders its application in lithium-ion batteries. Herein, polymer composite electrolytes were constructed utilizing three polymorphic Ce-MOFs as functional fillers to enhance its performance. The homogeneously dispersed Ce-MOF fillers restricted the reorganization of PVDF-HFP chains, thereby led to the change in crystallization and aggregation state of the polymer. Moreover, their porous structure and active sites also promoted the Lewis acid–base interactions with the polymer and TFSI⁻, promoting ion dissociation. Temperature-induced phase variation produced distinct porous crystalline structures formed the tetragonal-phase MOF-76-Ce exhibiting excellent properties with a room-temperature ionic conductivity of 7.89×10⁻⁴ S cm⁻¹ and a Li⁺ transference number of 0.79. The full cell assembled with this electrolyte and high-energy-density polyanionic LiMn_0.6Fe_0.4PO₄ cathodes demonstrated good cycling stability. It could reach discharge capacity of 147 mAh g⁻¹ at 0.2 C and a capacity retention of 91% after 200 cycles at 0.5 C under a high cutoff voltage of 4.5 V. This work offers an effective filler strategy for developing high-performance quasi-solid-state polymer electrolytes and highlights the crucial role of metal–organic framework topology in advancing safe and durable lithium metal batteries.

Graphical abstract

Cu/CuO–graphite core–shell structures (CGCSs) were synthesized at 700–1000 °C using a vertical thermal chemical vapor deposition (V-CVD) system and fabricated into NH₃ gas sensors by screen printing. Structural characterization confirmed a Cu/CuO core encapsulated by a multilayer graphene shell whose crystallinity improved with synthesis temperature. Among the screen-printed line electrodes, those prepared from CGCSs synthesized at 1000 °C exhibited the lowest resistance and the best line-to-line uniformity, and were therefore selected for NH₃ sensing. The sensor shoed two response regimes separated by a transition at 600 ppm: a steep, nonlinear chemisorption-dominated response well described by the Langmuir model below 600 ppm, and a gradual, linear physisorption-dominated response above it. Reproducible sensing below 600 ppm was confirmed after thermal desorption at 140 °C. The binding energies of NH₃ on the CGCS surface (0.546 and 0.530 eV) indicate that the Cu/CuO core serves as the primary adsorption site, while the graphite shell provides an efficient charge-transport pathway. These results demonstrate that functional NH₃ gas sensors can be realized through a simple screen-printing process, without recourse to complex semiconductor fabrication.

Hexavalent chromium (Cr^VI) is a highly toxic, carcinogenic and hence severe environmental pollutant. Therefore, the exploitation of a cost-efficient, easy-to-operate and highly responsive method for the determination of Cr^VI has become an urgent task. In the present study, biomass derived carbon dots (PA-CDs) were easily obtained by using plantago asiatica (PA) as a carbon precursor through hydrothermal method. The PA-CDs exhibited a maximum emission at 443 nm with an excitation at 360 nm, with a high quantum yield of 19.67%. Notably, the PA-CDs were successfully applied as a fluorescence probe for the detection of Cr^VI grounded on the inner filter effect mechanism. Additionally, a PA-CDs soaked paper-based sensor was constructed, which exhibited excellent sensing performance, achieved the smartphone supporting portable detection with a limit of detection (LOD) of 64 nM. This work provide a feasible strategy of synthesis and application for biomass derived CDs, which exhibited broad prospects in protection of environment and human health. Furthermore, the PA-CDs-Cr^VI, a quenched fluorescence system (on-off) is capable of fluorescence restoration (off-on) triggered by ascorbic acid (AA), thereby realizing a cascade detection platform for the quantitative assaying of AA.

Graphical abstract

Heterojunction thin films undoped WS₂/p-Si and V-doped WS₂/p-Si were fabricated using the chemical bath deposition method. X-Ray diffraction analysis reveals that all three thin-film samples exhibit a crystallinity index of ~ 90%. The crystallite size of the thin films was found to range from approximately 130 to 238 nm. Field emission scanning electron microscopy indicates that the morphology of the pure WS₂ is spherical, whereas the morphology of the doped WS₂ appears petal-like due to the effect of doping. The optical properties of the deposited thin films were investigated using UV–visible and photoluminescence spectroscopy techniques. The results of this study indicate that the optical band gap lies between approximately 2.36 and 2.72 eV within the visible spectrum. The photoluminescence emission spectrum shows multiple peaks in the 420–620 nm range. Current–voltage characteristics were observed under dark conditions and at various wavelengths. The calculated ideality factor ranged from 1.37 to 3.63, indicating proximity to the theoretical ideal diode value. As the vanadium content increases, the thin films exhibit shorter response and recovery times. Under a forward bias condition of 5 V, the device exhibits the fastest recovery and response times. This characteristic enables it to function effectively as a photodetector across a broad spectrum of wavelengths, from the near infrared to the ultraviolet.

Graphical abstract

Mg/Al composites are promising for lightweight applications but are often limited by brittle interfacial intermetallic compounds (IMCs). This study fabricated Mg/Al composites with 3D porous copper mesh interlayers (20‑ and 100‑mesh) via extrusion‑shear processing. Results show that the 100‑mesh copper mesh interlayer effectively suppresses IMC growth, reduces the bonding layer to 5.5 μm, refines Mg grains (5.74 μm), and weakens basal texture, forming a defect‑free interface. The synergistic effects of stress distribution optimization, metallurgical‑mechanical bonding, and enhanced dislocation density lead to an interfacial shear strength of 29.96 MPa. In contrast, the 20‑mesh copper mesh interlayer induces stress concentration and interfacial cracking, degrading bond strength. This work provides insights for designing high‑performance Mg/Al interfaces through porous interlayer engineering.

In recent years, p-type semiconductor nanomaterials have garnered significant interest for their application in the detection of toxic and hazardous gases due to their good catalytic performance, which facilitates the acceleration of reaction kinetics. In this work, we successfully synthesize the hollow flower-like In-doped NiO. The gas sensitivity tests result that the 1 at% In–NiO-based sensor displays improved gas performances in detecting triethylamine (TEA). Specifically, the response to 50 ppm TEA is 10 at 220 °C, representing a fivefold enhancement compared to pure NiO-based sensor. Combined with the improved selectivity and response/recovery speed, the synthesized 1 at% In–NiO material can effectively detect TEA. This study presents a viable strategy for enhancing the gas sensitivity of NiO and explores the enhanced gas sensing mechanism by discussing the advantages of the hollow structure, electron transport and abundant oxygen vacancies induced by indium doping.

Graphical abstract

The hollow flower-like In-doped NiO sensors show the enhanced response and selectivity performance to TEA.

Natural cellulosic fibers such as hemp are increasingly important for sustainable textiles, biocomposites, and eco-friendly structural materials, where mechanical performance is governed largely by how water is managed during processing; understanding water-induced reinforcement of these fibers is, therefore, essential for the reliable manufacture of high-performance, low-carbon fiber-based products. This work presents a multiscale investigation into how water governs the transition from a hydrated state to a fully dried structure and, in doing so, enhances hemp fiber interactions after wetting. In the wet state, COMSOL multiphysics simulations show that microscopic water bridges generate capillary forces that draw neighboring hydrophilic fibers together and initiate structural densification. As drying progresses and water gradually evaporates, molecular dynamics simulations reveal that the remaining adsorbed water reorganizes into a hydrogen-bond network that reinforces the contacts between cellulose chains. Experimental tensile tests conducted under controlled humidity conditions further demonstrate that hemp inter-fiber cohesion changes systematically with moisture content and reaches a maximum when capillary compaction and hydrogen-bond formation both contribute to cohesion. These findings clarify how water, during its removal from the material, sequentially enables capillary-driven packing and molecular-level bonding. The combined insight provides a mechanistic basis for cellulosic fiber processing and application.

Epoxy resins (EP) are widely used in construction, automotive, and aerospace industries owing to their excellent mechanical and chemical properties, yet their flammability and toxic combustion products restrict their use in higher-safety applications. To improve the flame retardancy and smoke suppression properties of epoxy resin (EP), a core–shell PDA@β-FeOOH was prepared by in situ polydopamine coating of rod-like β-FeOOH, which was then assembled on graphene oxide (GO) nanosheets to construct a novel hybrid flame retardant (GO@PDA@β-FeOOH). With the incorporation of 7 wt.% GO@PDA@β-FeOOH, the EP composite received a V-0 rating per the UL-94 standard and elevated LOI to 30.13%. In comparison with pure EP, the composite showed reductions of 19.1%, 22.3%, 65.3%, and 26.1% in heat release rate (HRR), total heat release (THR), total smoke production (TSP), and peak CO₂ production (CO₂P), respectively, confirming significantly enhanced flame retardancy and smoke inhibition. According to the characterization results, β-FeOOH serves as a radical scavenger in the gas phase, effectively disrupting chain reactions during combustion. Simultaneously, in the condensed phase, the physical barrier layer is strengthened through the multiple actions of GO@PDA@β-FeOOH, including the lamellar barrier effect of GO, the catalytic carbonization by β-FeOOH, and the dehydration and carbonization of PDA. Thus, GO@PDA@β-FeOOH synergistically conferred flame retardancy on EP in both the gaseous and condensed phases. In addition, the mechanical properties of EP/GO@PDA@β-FeOOH exhibited well. The intercomponent synergy of nanofillers achieved in this work may provide a viable route for the development of high-performance epoxy composites with excellent flame retardancy while retaining mechanical performance.

Graphical abstract