Journal of Materials Science最新文献

NiCo-based basic carbonates (NiCoBC) have the advantages of high theoretical specific capacitance, low cost and good stability. To further enhance the electrochemical performance of NiCoBC, a composite material (NiCoBC@HC) of NiCoBC and carbon derived from Holly leaves was prepared in this study. The NiCoBC@HC electrode achieved a high specific capacitance of 385.8 F g⁻¹ at 1 A g⁻¹, which was 2.2 times that of the carbon-free NiCoBC electrode. The rate performance of NiCoBC@HC is also higher than that of NiCoBC. The excellent performance of NiCoBC@HC stems from the synergy between NiCoBC and HC. The electrochemical performance of NiCoBC@HC is also higher than that of NiCoBC and various high-cost carbon material (such as graphene, graphene oxide, multi-walled carbon nanotubes, hydroxylated or carboxylated multi-walled carbon nanotubes) composites, indicating that HC has significant advantages and can reduce the production cost of electrode materials. NiCoBC@HC electrodes are assembled into an asymmetric supercapacitor (ASC) with the structure of NiCoBC@HC//activated carbon (AC). This device has a high energy density of 19.3 Wh kg⁻¹ at 400 W kg⁻¹. This research provides innovative ideas for the high-value utilization of biomass and lays an experimental foundation for the development of low-cost and sustainable electrode materials.

The present work investigated the influence of pre-annealing on recrystallization behavior and texture evolution of a tensile-twin-containing Zr702. A novel multi-directional rolling (MDR) at liquid nitrogen temperature was utilized to introduced dense tensile twins in Zr702. Simple annealing at 650 ℃ for 30 min and pre-annealing at 500 ℃ for 30, 60 and 90 min or at 550 ℃ for 10, 20 and 30 min followed by annealing at 650 ℃ for 30 min were performed on the MDR samples. The conventional discontinuous recrystallization occurred in twinned grains during simple annealing at 650 ℃ for 30 min, which resulted in a recrystallization texture of (langle 0001rangle) close to transverse direction (TD). A small number of recrystallized grains formed during pre-annealing at 500 ℃ for 90 min and at 550 ℃ for 30 min, which exhibited a texture of (langle 0001rangle) close to TD and (langle 0001rangle) aligned on normal direction (ND) respectively. Pre-annealing at 500 ℃ for 30 and 90 min did not change the recrystallization behavior and texture during followed annealing at 650 ℃. Pre-annealing at 500 ℃ for 60 min resulted in oriented nucleation and preferred growth during followed annealing at 650 ℃, which generated a bimodal basal texture with the (langle crangle) axes close to ND. Pre-annealing at 550 ℃ for 10 min promoted the formation of texture component of (langle crangle) axes close to ND during the early stage of followed annealing at 650 ℃, however, which did not affect the final recrystallization texture. Pre-annealing at 550 ℃ for 20 and 30 min did not affect the recrystallization behavior and texture during followed annealing at 650 ℃. The recrystallized grains formed at 550 ℃ for 30 min contributed little to the final texture.

This research aims to investigate and compare the effect of conventional sintering and two-step sintering (TSS) techniques on the microstructural, structural, dielectric, multiferroic, and magnetodielectric (MD) properties of 0.9BaTiO₃ (BTO)–0.1CoFe₂O₄ (CFO) composites and their pure constituents. By incorporating the CFO into the matrix, the BTO’s tetragonality factor diminished while its unit cell expanded. Among the composites, the TSS1 (sintering program: 1400 °C for 1 min, followed by 1300 °C for 20 h) indicated the greatest dielectric (dielectric constant of ~ 1721 and dielectric tangent loss of ~ 0.147) and ferroelectric properties (saturation polarization of ~ 12.57 µC/cm² and remanent polarization of ~ 10.51 µC/cm²) due to its highest relative density (95%). The saturation and remanent magnetizations of the composites were in the same range (~ 4.3 and ~ 0.5 emu/g, respectively) due to their chemical composition-dependent character. Moreover, the coercivity was diminished by increasing the relative density, as it is affected by the microstructure. Finally, the largest MD coefficient (~ 2.5%) was acquired for the TSS1 composite at 7 kOe.

Graphical abstract

The development of efficient and cost-effective catalytic systems for antibiotic degradation remains a significant challenge in environmental remediation. Herein, a novel Co/CuFe₂O₄ composite was synthesized via a sol–gel combustion method to construct a multi-metal synergistic photocatalytic-Fenton-like system for the degradation of oxytetracycline (OTC). Density functional theory (DFT) calculations indicate that the incorporation of Co leads to a more negative material formation energy, suggesting that Co/CuFe₂O₄ has a more stable electronic structure. This optimized electronic structure enhances the redox cycle (Fe³⁺/Fe²⁺, Cu²⁺/Cu⁺, and Co²⁺/Co³⁺), thereby improving the activation efficiency at low concentrations of H₂O₂ (0.1–6 mmol/L). Under optimal conditions (pH 3, 35 °C, 4 mmol/L H₂O₂), the 13% Co/CuFe₂O₄ catalyst achieved complete OTC degradation within 60 min, with an 0.1 mmol/L H₂O₂ utilization rate of 17.81% at neutral pH. Moreover, the catalyst exhibited excellent stability, retaining 87.5% degradation efficiency after five cycles. Radical quenching experiments confirmed that ·OH, h⁺, and ·O₂⁻ were the dominant reactive species, while the synergistic effect of multiple metal redox pairs facilitated efficient electron transfer and H₂O₂ activation. This work provides a promising strategy for designing high-performance Fenton-like catalysts with broad pH adaptability and low oxidant consumption, offering significant potential for the treatment of antibiotic-contaminated wastewater.

Graphical Abstract

The nanotwin structure not only maintains the excellent electrical conductivity of the Cu alloy but also enhances its strength. Based on the microstructure of Cu-Ag alloys observed by transmission electron microscopy (TEM), molecular dynamics (MD) models of Cu-Ag polycrystalline alloys with different twin spacings were established in this study. By adjusting key parameters such as temperature and twin spacing, the mechanical properties and intrinsic deformation mechanism of Cu-Ag polycrystalline alloys were investigated. Studies have shown that the classic Hall–Petch (H-P) relationship has a distinct applicable range at the nanoscale. When the twin spacing is less than 7. 0 nm, the classical H-P relationship is observed. Otherwise, the opposite H-P relationship is observed. In addition, temperature has a significant impact on the mechanical properties of materials. As the temperature rises, the Young’s modulus decreases due to the reduction in dislocation density, and the slope changes at 500 K. These findings provide guidance for the design of high-performance Cu-Ag alloys.

Foldable electronic devices require polymer cover films with reliable coating integrity under repeated bending. In this work, the bending-induced failure behavior of an acrylic hard coat layer on isotropic and anisotropic PET substrates is systematically investigated. Low-temperature inward bending tests reveal pronounced substrate- and orientation-dependent damage morphologies, including differences in crack opening, crack continuity, and damaged-zone width. Tensile characterization shows that substrate stiffness, strength, and ductility along the bending direction strongly affect the tolerance of coating to bending deformation. Wide angle X-ray scattering indicates that cyclic loading has little influence on overall crystallinity, whereas the stability of crystalline orientation varies significantly with substrate anisotropy. PET films with highly aligned and orientation-stable crystalline structures exhibit suppressed crack opening and improved resistance to bending-induced damage. By correlating coating fracture morphology with substrate mechanical properties and microstructural stability, this study demonstrates that bending durability of hard-coated PET films is primarily governed by substrate mechanical response and orientation stability rather than coating composition alone. These results provide practical guidelines for substrate selection and structural optimization of cover film systems in foldable display applications.

In the present time, the need of sustainable and clean energy has increased the worldwide interest in photocatalytic water splitting since it is a promising mean of hydrogen production. Considerable attempts have been made to synthesize an effective photocatalyst. Among various photocatalysts, V₂O₅ has attracted considerable interest because of its distinctive chemical, optical, and photochromic properties. This review emphasizes the current progress in V₂O₅ as a potent visible light photocatalyst, focusing on its photocatalytic reaction mechanism, various synthesis methods and photocatalytic performance improvement strategies for higher hydrogen yield. Different synthesis approaches, such as chemical vapor deposition, electron beam deposition, pulsed laser deposition, sol–gel and hydrothermal methods are reviewed in this article. Moreover, the effect of various dopants on the catalytic performance of V₂O₅ and the underlying mechanism for enhanced hydrogen production by doped V₂O₅ has been elaborated. Furthermore, different catalytic setups comprising a variety of V₂O₅-based heterojunctions, i.e., types I, II and III, have been explained along with their photocatalytic performance for higher hydrogen conversion efficiency in comparison to the pristine V₂O₅. Hence, the current review can offer significant insights for enhanced solar to hydrogen conversion efficiency via V₂O₅-based photocatalysts, thereby fulfilling the energy needs of the industrial sector.

Graphical abstract

The mechanical performance of Ti₂AlNb alloys is critically influenced by interstitial elements, yet their atomic-scale effects remain insufficiently understood. In this study, first-principles calculations were employed to systematically investigate the influence of four representative interstitial atoms (B, C, N, and O) on the structural and mechanical properties of O-phase and B₂-phase in Ti₂AlNb alloys, as well as on the O(001)/B₂(110) interface. The results reveal that interstitial doping induces lattice expansion. Although O-phase and B₂-phase each contain two distinct interstitial sites, the thermodynamic incorporation preference is consistent across both, following the sequence N > C > O > B in O-phase and O > B > C > N in B₂-phase. Mechanically, all interstitials enhance the stiffness of the B₂-phase but reduce its ductility, whereas nitrogen uniquely strengthens the O-phase, while interstitial doping generally improves its ductility. Furthermore, nitrogen exhibits a pronounced site preference near the O/B₂ interface and enhances interfacial cohesion by significantly increasing the work of separation through covalent bonding with neighboring Ti, Al, and Nb atoms. Experimental results demonstrate that the incorporation of nitrogen into Ti₂AlNb alloys leads to a significant increase in tensile strength from 945 to 1092 MPa, which can be primarily attributed to the combined effects of solid solution strengthening and grain refinement, and although a slight reduction in elongation is observed, the alloys still exhibit ductile fracture behavior. These findings elucidate the atomistic mechanisms by which interstitial species modulate mechanical behavior and provide a theoretical foundation for the targeted design of high-performance Ti₂AlNb-based alloys with improved interfacial integrity.