Valence Band‐Tunable NiFe Electrocatalyst Triggered by the Dynamic Mo Exudation and Re‐Deposition for Superior High Current Density Oxygen Evolution Reaction

Abstract Developing energy‐ and time‐efficient strategies to derive high‐performance non‐precious electrocatalysts for anodic oxygen evolution reaction (OER), especially stably working at industrial‐demanding current density, is still a big challenge. In this work, a concise molten salt erosion scenario was devised to rapidly modulate the smooth surface of the commercial NiMo foam substrate into the rough, electronically coupled, and hierarchically porous Ni/Fe/Mo(oxy)hydroxide catalyst layer assembled by the nanosphere array. This self‐supported catalyst is super‐hydrophilic for the alkaline electrolyte and distinguished by a balanced Mo leaching/surface‐readsorption process to tune the metal d band center and electronic perturbation. The altered electronic environment with the favored OER intermediate adsorption behavior attains the outstanding OER activity in terms of a very small overpotential of 230.21 mV at 10 mA cm −2 and an ultra‐long stability for 1179.45 h to sustain the initial commercial‐level current density of ca. 1000 mA cm −2 . This superb performance transcends most of the edge‐cutting transition metal peers reported recently and can satisfy the standards of industrial applications. This industrial‐compatible synthesis technology holds profound implications for hydrogen production via water splitting and other electrochemical applications.