SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3685-7
NiMo-based catalysts are promising for the hydrogen evolution reaction (HER), yet optimizing their electronic structure and enhancing mass transfer remain challenging. Here, we report a route to synthesize two-dimensional (2D) porous Mo2N-Ni heterojunction nanosheets with tuned Ni/Mo ratio for enhanced alkaline HER. The precursor is assembled from polyoxometalate clusters (PMo12) and layered Ni(OH)2. The interaction between PMo12 and Ni(OH)2 suppresses particle agglomeration during pyrolysis, yielding 2D porous sheets composed of small Mo2N-Ni units. Electron transfer from Ni to Mo2N redistributes electrons at the heterojunction, optimizing intermediate adsorption/desorption. The porous structure enhances mass transfer, reducing catalyst impedance. The optimized catalyst exhibits an overpotential of 19 mV at 10 mA cm−2, comparable to commercial Pt/C. An anion exchange membrane (AEM) electrolyzer pairing this catalyst with NiFe-LDH achieves 500 mA cm−2 at 1.80 V and operates stably for 300 h. This assembly method offers a scalable strategy for efficient catalyst production.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608021
To address the significant increase in fine particulate matter (PM2.5) and its chemical component concentrations caused by the concentrated setting-off of fireworks and firecrackers during the Spring Festival in Yancheng City, this study introduced the Bayesian-optimized XGBoost model (BO-XGBoost) based on PM2.5, particulate component, and meteorological observation data. The model simulated non-setting-off baseline concentrations using meteorological factors as independent variables, enabling quantitative assessment of setting-off contributions. Results showed that the concentrated setting-off exerted significantly differentiated effects on various pollutants. Among water-soluble ions, K+ and Mg2+ were core characteristic tracers, with concentrations reaching 15.89 and 20.08 times baseline levels on Lunar New Year's Eve, directly reflecting high-intensity emissions. Secondary conversion ions such as SO4^2- and NO3^- showed sustained high contributions on both Lunar New Year's Eve and the fifth day of the first lunar month, reflecting cumulative effects of atmospheric chemical transformation. Among inorganic elements, K, Ba, and Sr were core characteristic tracers, with concentrations showing explosive growth on Lunar New Year's Eve, serving as direct fingerprints of fireworks. Elements such as Pb and Mn were also significantly affected, reflecting direct heavy metal emissions. Temporal comparisons indicated that emission intensity on Lunar New Year's Eve was significantly higher than on the fifth day, with increased proportional contribution of secondary conversion processes on the fifth day. The study achieved accurate quantification of setting-off contributions through a data-driven model, clarifying pollution fingerprint characteristics and temporal differentiation patterns, providing scientific basis for air quality management and policy optimization during the Spring Festival.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4051-x
Graphite lubricants are critical for high-quality and high-efficiency drawing of refractory metal wires, yet inadequate dispersion stability frequently challenges their practical application. Inspired by the bio-surfactant synergic mechanism that combines different bio-surfactants to collectively reduce surface energy and friction, a binary anionic surfactant system comprising sodium dodecyl benzene sulfonate (SDBS) and sodium lignosulfonate (SL) was engineered to enhance dispersion and stability via a synergistic effect. The synergistic parameter β was calculated to be −2.34, indicating strong synergism. The resulting graphite lubricants maintained homogeneous dispersion for up to 60 days. Molecular dynamics (MD) simulations combined with density functional theory (DFT) calculations confirmed that the synergistic effects originate from steric hindrance, electrostatic repulsion, π-π stacking, and hydrogen bonding. These hierarchical secondary interactions collectively increased the interfacial formation energy at the graphite/surfactant/water tri-phase interface, thereby effectively wetting particle powders and enhancing stability. During metal wire drawing, the graphite lubricants reduced the friction coefficient between the die and metal wires to 0.06, ultimately enabling drawn tungsten wires with superior surface integrity, expanded loop diameter, and enhanced tensile strength relative to single-surfactant benchmarks. This study provides experimental and theoretical guidance to design effective graphite lubricants for high-quality drawn metal wires.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4126-0
Flexible X-ray detectors are constrained by the difficulty of producing semiconductor films that simultaneously exhibit uniform morphology, high crystallinity, and mechanical robustness. Here, we introduce a hydrogen-bond engineered supramolecular (HBES) strategy to overcome these limitations in supramolecular bismuth halide clusters (PDBiI5). By incorporating polyacrylic acid (PAA), a dynamic supramolecular network is formed that suppresses the coffee-ring effect during ultrasonic spray-coating via increased solution viscosity and controlled kinetic balance between solvent evaporation and solute diffusion. The HBES approach also modulates crystallization kinetics, extending crystal growth time from 23 to 41 s, yielding densely packed films with enhanced crystallinity and reduced defect states. These improvements lead to superior charge transport: a hole mobility of 2.16 cm2 V−1 s−1 and a mobility-lifetime product of 9.1 × 10−4 cm2 V−1. The resulting X-ray detectors achieve a record sensitivity of 19,009 μC Gyair−1 cm−2 and an ultralow detection limit of 3.35 nGyair s−1, with excellent operational and environmental stability. Leveraging the mechanical robustness from the supramolecular network, we demonstrate the first direct-type flexible X-ray imager, retaining 85% performance after 1000 bending cycles. This imager overcomes geometric distortion and vignetting, maintaining 85% edge photocurrent versus 58% for rigid detectors, enabling clear imaging of curved objects. This work establishes a versatile supramolecular engineering paradigm for high-performance flexible X-ray detection and imaging.