SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4235-6
Fluorite-structured oxides (HfO2, ZrO2) are promising for resistive random-access memory (RRAM) due to their scalability and tunable properties. However, achieving high resistive switching on/off ratios remains challenging. Here, we report a collaborative strategy combining Hf/Zr ratio optimization and Lu3+ doping to regulate band structure and oxygen vacancy concentration in Hf0.4Zr0.6O2 (LHZO) thin films. The resulting LHZO devices exhibit a resistive switching ratio of 8.4 × 10^4, two orders of magnitude higher than that of ZrO2 (1.2 × 10^3). Electrical characterization and synchrotron radiation photoemission spectroscopy reveal that Lu doping widens the bandgap to 4.95 eV, downshifts the valence band, and introduces defect states, collectively suppressing p-type conductivity and reducing off-state leakage current. Simultaneously, Lu3+ doping enriches oxygen vacancies, stabilizing ohmic conductive filaments in the on-state. This co-optimization of band structure and oxygen vacancies effectively enhances insulating properties in the high-resistance state and ohmic conductivity in the low-resistance state, leading to superior resistive switching performance with robust retention (>10^4 s). Our findings establish a fundamental strategy for tailoring electronic properties of doped HfZrO2 thin films toward high-performance RRAM applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3506-3
Metallic glasses (MGs) often suffer from sluggish hydrogen evolution reaction (HER) kinetics in neutral and alkaline media, with their catalytic performance predominantly confined to acidic environments. Herein, we reported a novel thermoplastic forming technique to fabricate a self-supported partially crystallized nanoporous Pt56.2Ni5.2Cu16.8P21.8 metallic glass (C-NPMG). The C-NPMG catalyst delivers ultralow overpotentials of 18.0 mV (0.5 M H2SO4), 42.2 mV (1 M KOH), and 88.0 mV (1 M phosphate-buffered saline (PBS)) at a current density of 10 mA cm−2, outperforming most state-of-the-art non-noble MGs and Pt-based benchmarks across all pH conditions. Notably, it maintains negligible performance decay for over 1000 h in alkaline electrolytes, showcasing superior stability. Experimental and computational analyses reveal that the enhanced HER activity arises from three synergistic effects: (1) the high-specific-surface-area nanoporous architecture that maximizes active site exposure; (2) the formation of crystallite-amorphous interfaces during partial crystallization, which lowers the energy barrier for H2 desorption; (3) the hierarchical super-hydrophilic and super-hydrophobic wettability of the C-NPMG, which optimizes mass transport and prevents electrolyte-induced corrosion. This work establishes a novel design paradigm for developing high-performance, pH-universal HER electrocatalysts by integrating structural nano-engineering and crystallite-amorphous phase synergy in metallic glass systems to overcome the trade-offs between performance and stability in electrochemical water splitting.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510034
Phosphonate wastewater, characterized by stable C–P bonds, poses significant environmental risks due to its resistance to degradation and potential to contribute to eutrophication. This study developed a chloride-enhanced Fe(II)/PMS/H2O2 system for the oxidative degradation of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) and simultaneous recovery of phosphorus as iron phosphate (FePO4). Under optimal conditions (0.1 mmol/L PBTC, 1.0 mmol/L Fe(II), 0.5 mmol/L PMS, 0.5 mmol/L H2O2, 10 mmol/L NaCl, initial pH 3.0, 60 min), total phosphorus (TP) removal reached 100%, with phosphorus nearly completely recovered as FePO4 precipitate. Increasing NaCl concentration and temperature enhanced TP removal, while pH significantly influenced removal efficiency and product speciation; acidic conditions (pH < 4.3) favored FePO4 precipitation. Coexisting Ca2+ and Mg2+ had negligible effects, whereas HCO3− and humic acid (HA) inhibited TP removal in a concentration-dependent manner. Radical quenching and electron spin resonance (ESR) analyses identified hydroxyl radicals (•OH), ferryl ion (Fe(IV)=O), sulfate radicals (SO4•−), and chlorine radicals (Cl•) as primary reactive species, with •OH playing a dominant role. Chloride introduction promoted the generation of multiple reactive species, and Cl• and its derivative Cl2•− directly attacked the C–P bond and phosphonate group, facilitating phosphorus release as PO43− and subsequent FePO4 formation. The system's feasibility was validated using actual industrial circulating cooling water. This study provides a novel approach for phosphonate wastewater treatment and phosphorus recovery.