Engineering Active Site Reconstruction of Metal Hydroxide/Metal Molybdate Heterogeneous Interface Enhances the Electrochemical Water Oxidation Process

Efficient, stable and economical water electrolysis catalysts are of paramount importance in energy transition and storage systems. Although numerous single compounds exhibit certain electrocatalytic properties, their inherent limitations hinder optimal performance. In this article, a highly active electrode was synthesized by constructing a heterojunction between Fe2(MoO4)3 and Ni(OH)2. As expected, the Ni(OH)2/Fe2(MoO4)3@TM heterojunction catalytic electrode demonstrated remarkable activity for water oxidation in a 1.0 M KOH electrolyte, exhibiting a low overpotential of 265 mV (at 10 mA cm-2 current output) while maintaining excellent stability. This superior performance was validated through electrochemical tests, DEMS, TEM, Raman spectroscopy and DFT calculations. The results indicate that the constructed heterojunction electrode, due to its synergistic effect, optimizes the d-band center, modulates the adsorption energies of *OH and *O at the electrode interface, facilitates electron transfer and surface reconstruction of the catalyst, and thereby enhances OER activity and stability. The synergistic effect caused by interface and reconstruction engineering can provide a new idea for the design of efficient and stable OER electrocatalysts.