High-performance oxygen evolution reaction via self-optimizing interface engineering with simultaneous activation of dual-sites of surface oxyhydroxides

Metal oxyhydroxides produced by the surface reconstruction were widely considered as active catalytic species in the oxygen evolution reaction (OER). However, simultaneous activation of metal sites in surface oxyhydroxides remains a great challenge. In this study, the interface self-activation strategy was utilized to simultaneously activate both the iron and nickel sites at the surface oxyhydroxides of (Fe,Ni)OOH-NiSe2 nano heterostructure. The OER activity was greatly boosted by the dual activation of active sites, resulting in an overpotential of 245 mV@100 mA cm−2 with a small Tafel slope of 44 mV dec−1. The finely constructed FeOOH-NiSe2 heterostructure was transformed into (Fe,Ni)OOH-NiSe2 through the formation of distinct bonds of M(Fe,Ni)-O-Se during the OER process, which was discovered through a combination of experimental studies with DFT calculations. A fast OER reaction dynamic was achieved due to the unique self-optimized interface structure which produced a dual synergistic effect between the interface structure and the active sites of Fe and Ni of oxyhydroxides, modulated the electronic structure and d band center of active sites, and increased the number of optimum active sites. This work paves a way to design high-performance electrocatalysts with multiple active sites for other electrochemical reactions.