Corrosion-Engineered Mo-Containing FeCo-(oxy)hydroxide Electrocatalysts for Superior Oxygen Evolution Reaction

3d metal oxide/hydroxides are promising catalysts for the oxygen evolution reaction in recent years. However, further improvement of their catalytic activity is challenging due to their low conductivity and the similarity among the electronic structures of neighboring 3d metal modulators. Herein, FeCo-(oxy)hydroxide nanosheet arrays containing Mo grown directly on Fe foam (FF) are synthesized by a cost-effective and energy-efficient corrosion engineering method, which is realized via the controlled oxygen corrosion reaction of FF. Furthermore, the introduction of high-valence Mo can efficiently regulate the electronic coordination environment, and the control of the corrosion time can fabricate amorphous-crystalline heterostructures. Therefore, the as-prepared catalyst exhibits superior catalytic performance with an ultralow overpotential of 212 mV to reach a current density of 100 mA cm–2. The results show that the corrosion engineering method and introduction of high-valence metal modulators are favorable directions for the development of high-activity and cost-effective electrocatalysts. Interestingly, this method is universal and can be easily extended to other metal oxide composites.