SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4192-y
Electrochemical water splitting is pivotal for scalable green hydrogen production, yet its practical deployment hinges on cost-effective electrocatalysts with high activity and durability. This study introduces a low-cost, three-dimensional (3D) nanoporous ZrVFeCoNi material fabricated via chemical dealloying, at merely 0.16% of the cost of Pt. The structure-activity relationship between its microstructure and hydrogen evolution reaction (HER) performance was systematically explored. Lattice defect effects from multiphase intermetallic compounds, combined with multi-metal synergy, optimize H+ adsorption energy and electron transfer kinetics. The 3D nanoporous architecture provides a high electrochemical surface area with abundant active sites, enhancing electrolyte penetration and reducing interfacial mass transfer resistance. Consequently, the ZrVFeCoNi electrode exhibits outstanding HER performance, requiring only a 38 mV overpotential to reach 10 mA cm−2 and maintaining stable operation for 1000 h at 500 mA cm−2. Integrated into a full water electrolyzer (ZrVFeCoNi || IrO2/Ni), the system achieves a cell voltage of 1.60 V at a current density of 400 mA cm−2. Advanced characterization and density functional theory (DFT) calculations reveal that interfacial interactions and charge transfer at heterointerfaces drive catalytic activity, showcasing the potential of 3D nano-structured multiphase intermetallic compounds as high-performance electrocatalysts for green hydrogen systems.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606016
Barium slag, a solid waste from barium salt production, poses environmental risks due to high sulfur and soluble barium content. This study investigated the desulfurization of barium slag using sodium carbonate (Na2CO3) as a precipitating agent. The effects of reaction temperature, time, and Na2CO3 concentration on desulfurization efficiency were systematically evaluated. X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) were employed to analyze phase transformations and microstructural evolution. Results showed that desulfurization primarily proceeds via the reaction of ettringite (Ca6(Al(OH)6)2(SO4)3·26H2O) with Na2CO3, forming calcium carbonate (CaCO3) precipitates. However, the precipitated CaCO3 accumulates on ettringite surfaces, hindering further reaction. Under optimal conditions (60 °C, 5 h, 2 mol/L Na2CO3), the desulfurization efficiency reached 91.21%, reducing sulfur content in the slag to 0.27%, meeting the HJ 662—2013 standard for cement kiln co-processing. This work provides a mechanistic basis for efficient and environmentally sound treatment of barium slag, supporting its resource utilization in cement production.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4334-9
Piezoelectric materials underpin modern electromechanical energy conversion, serving as critical components in sensors, actuators, and energy harvesters. Their performance is intrinsically governed by the piezoelectric coefficient, yet optimizing this property remains challenging due to the profound influence of diverse microscopic structures. This review systematically examines three fundamental crystalline architectures—perovskite, wurtzite, and fluorite—and critically analyzes performance optimization strategies tailored to each structure. We explore five principal modification approaches: defect engineering, elemental doping, heterostructure film fabrication, composite film design, and buffer layer incorporation, with emphasis on the underlying physical mechanisms that drive property enhancements. By providing a cross-structural comparison, this review establishes clear structure–property relationships, offering a foundational guide for material selection and design. Furthermore, we highlight the implications of these advanced materials for next-generation applications in energy harvesting and smart devices. Finally, we present a forward-looking roadmap, outlining emerging research directions and addressing key technical challenges to guide the development of next-generation high-performance piezoelectric materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4229-6
The escalating retirement of lithium-ion batteries (LIBs) necessitates efficient recycling technologies to recover cathode materials, particularly lithium iron phosphate (LFP), which dominates the traction battery market. Conventional pyrometallurgical and hydrometallurgical methods are energy-intensive and environmentally burdensome. Here, we report a fluorine doping-assisted direct regeneration strategy for spent LFP (SLFP) cathodes, yielding a regenerated LFP-F (RLFP-F) with a hybrid structure of ordered crystalline and disordered domains. Fluorine doping reduces the Li+ diffusion energy barrier, as evidenced by density functional theory calculations, and strengthens Fe–O bonding, suppressing Fe migration and anti-site defect formation. The O 2p band center shifts downward, increasing the Fe 3d–O 2p energy separation from 3.23 eV in pristine LFP to 3.46 eV in RLFP-F, enhancing structural stability and electronic conductivity. Electrochemical tests demonstrate that RLFP-F delivers a high-rate capability and excellent cycling stability. Life-cycle assessment reveals that direct regeneration consumes only 9.986 MJ kg−1 and emits 0.324 kg CO2-equivalent per kg of cell, significantly outperforming pyrometallurgy and hydrometallurgy. Economic analysis based on 2025 Chinese market prices indicates a net profit of $397.15 per ton of SLFP battery recycling, attributed to the closed-loop cathode-to-cathode design. This work provides a sustainable and economically viable route for upcycling spent LFP batteries.