Regulating the electronic structure of cobalt selenide by doping engineering for efficient oxygen evolution reaction

Transition metal selenides are a highly promising class of electrocatalysts in the field of alkaline oxygen evolution reactions (OER). However, due to the weak catalytic ability of intrinsic active sites and slow kinetic driving forces, the OER performance of single metal selenides is still unsatisfactory. Herein, we prepared a novel iron doped cobalt selenide nanospheres catalyst (FeCoSe) by introducing Fe in situ into CoSe during the solvothermal reaction process using a doping strategy. Density functional theory (DFT) calculations demonstrate that the incorporation of Fe effectively optimizes the d-band center of CoSe, thereby enhancing the catalyst's adsorption capacity for intermediates, reducing the reaction barrier for OER, accelerating the kinetics rate of OER, and ultimately improving the overall catalytic performance for OER. The optimal catalyst (FeCoSe-1:2) demonstrates exceptional OER performance in 1 M KOH electrolyte, exhibiting a low overpotential of 250 mV at a current density of 10 mA cm(- 2) and a small Tafel slope of 44 mV dec(- 1), surpassing the performance of the cobalt selenide. The catalyst also demonstrates excellent long-term stability during the OER process. This study will provide valuable reference for the development of durable alkaline OER catalysts, thereby facilitating the fabrication of advanced energy devices in future.