Cobalt-based selenide composite materials as high-efficiency electrocatalysts for oxygen evolution reaction

Abstract

Water electrolysis serves as a crucial pathway for the generation of renewable hydrogen energy, with the oxygen evolution reaction (OER) demanding more energy compared to the hydrogen evolution reaction (HER). Consequently, we prepared cobalt-based selenide composite materials (CS/XC-Ni) through chemical doping and heterojunction construction. CS/XC-Ni demonstrated outstanding OER performance when exposed to alkaline electrolytes. Specifically, at a current density of 10 mA·cm⁻², the overpotential was 334 mV, and the overpotential at a current density of 50 mA·cm⁻² was 435 mV, with a Tafel slope of 94 mV·dec⁻¹. Density functional theory (DFT) calculations indicate that the introduction of Ni optimizes the catalyst's O adsorption capability, while the construction of heterogeneous interfaces reduces the energy barrier of the rate-determining step. This demonstrates the great potential of Co/XC-Ni in oxygen evolution, providing new insights for the design and synthesis of efficient oxygen evolution catalysts.