Enabling high-efficiency alkaline overall water splitting via Mott-Schottky effect-driven Ni/NiFeMo-LDH interfacial charge regulation

Ni/NiFeMo-LDH Schottky heterostructure was constructed by an electro-deposition method. • Accelerated charge transfer and reconstruction boost OER/HER kinetics. • Delivers 280 mV for OER and 250 mV for HER at 100 mA·cm −2 with long-term stability. Layered double hydroxides (LDHs) are promising OER catalysts but suffer from poor conductivity, slow interfacial charge transfer, and limited stability at high current densities. Here, we couple crystalline Ni-rich domains with an amorphous/poorly crystalline Ni-Fe-Mo hydroxide/oxyhydroxide-rich layered phase to form a conductive Mott-Schottky-type heterointerfacial architecture. The shift in XPS binding energy is consistent with interfacial electron coupling and possible charge redistribution. Electrochemical impedance measurements revealed a decrease in charge transfer resistance, and in situ Raman spectroscopy independently identified potential-induced reconstruction toward Ni(Fe)OOH-related active species. The resulting electrode achieves low overpotentials of 280 mV for OER and 250 mV for HER at 100 mA·cm −2 . Under near-industrial conditions (80 °C, 30% KOH), an AEM electrolyzer operates stably for 40 h with negligible decay, demonstrating its strong practical potential and providing guidance for the design of in situ catalytic electrodes via Schottky heterojunctions. Download: Download high-res image (186KB) Download: Download full-size image