Zinc Substitution-Induced Subtle Lattice Distortion Mediates the Active Center of Cobalt Diselenide Electrocatalysts for Enhanced Oxygen Evolution.

Doping engineering has been an important approach to boost oxygen evolution reaction (OER) activity, while investigation on the dopant-induced modification of active sites and reaction kinetics remains incomplete. Herein, taking the cubic CoSe2 as an example, a universal strategy to synergistically achieve active sites and dynamic regulation is developed by incorporating low-valence Zn. It is revealed that regulation by Zn can facilitate reconstruction of the surface to form active Co oxyhydroxides under OER conditions. By combining theoretical calculations and characterization by various techniques, it is shown that the incorporation of Zn into CoSe2 can cause subtle lattice distortion and strong electronic interactions, thereby contributing to increased active site exposure and improved OER kinetics. Density functional theory simulations demonstrate that Zn incorporation synergistically optimizes the kinetic energy barrier by promoting co-adsorption of OER intermediates on a Co site and its adjacent Zn site. As a result, the modified CoSe2 NAs electrode shows optimized catalytic activity and excellent stability with the low overpotential of only 286 mV required to drive a current density of 10 mA cm-2 in an alkaline electrolyte.