Binder‐Free Fe ^III Cu ^I Mo ^IV Electrocatalysts for Durable Water Splitting at Industrial Current Density

ABSTRACT The development of highly active and durable electrocatalysts based on earth‐abundant Fe, Cu, and Mo via an energy‐efficient one‐pot synthesis marks a decisive advancement in alkaline water electrolysis. Herein, we report a ligand (isothiocyanate)‐assisted, coordination‐guided one‐pot strategy for the synthesis of an Fe ^III Cu ^I Mo ^IV electrocatalyst. Compositional tuning between Cu‐rich and Mo‐rich variants induces pronounced morphological evolution, including cubic and spherical structures. Among them, Fe ₃ CuMo ₁₁ , with an average particle size of 28 ± 6 nm, exhibits exceptional bifunctional activity in 1 m KOH, evidenced by overpotentials of only 85 mV for hydrogen evolution reaction (HER) at 10 mA cm ⁻² and 90 mV for the oxygen evolution reaction (OER) at 10 mA cm ⁻² along with a low Tafel slope of 70.2 mV dec ^{− 1} . Remarkably, a two‐electrode electrolyzer assembled using Fe ₃ CuMo ₁₁ /NF as both the anode and cathode achieves a cell voltage of merely 2.082 V at 200 mA cm ⁻² , maintaining exceptional operational stability for over 500 h under alkaline water electrolysis. The superior catalytic performance is attributed to synergistic coupling among FeOOH, Cu ₂ S, and MoS ₂ phases, which offer optimal adsorption energetics and accelerates charge‐transfer kinetics. Our study offers a robust platform for industrially relevant alkaline water electrolysis.