In Situ Generation of Molybdate‐Modulated Nickel‐Iron Oxide Electrodes with High Corrosion Resistance for Efficient Seawater Electrolysis

Abstract

The realization of seawater electrolysis requires the development of electrode materials that can meet the requirements of high activity, high selectivity, and corrosion resistance. Herein, this work successfully prepares a molybdate (MoO₄²⁻)‐modulated nickel‐iron oxide electrode for seawater electrolysis via a quick and easy thermal shock method, with high activity and extraordinary durability in oxygen evolution reaction (OER) for seawater electrolysis. The experimental analyses and theoretical calculations reveal that the in situ generated MoO₄²⁻ on the surface of electrode can modulate and stabilize the catalytic active phase γ‐(Ni, Fe)OOH, improving the OER activity, as well as play a critical role in protecting electrode from chloride ions (Cl⁻) corrosion for extended service life. This catalyst thus displays an evidently slow degradation rate of 20 µV h⁻¹ during a long‐term operation (>1500 h) at 100 mA cm⁻². This work provides a new viewpoint for the design of oxyanion‐modified catalysts and can be widely used to address the challenges in seawater electrolysis.