Iron-doped XC-72 enhancing cobalt selenide for high-efficiency oxygen evolution reaction.

As an emerging class of anodic catalyst material for water electrolysis and hydrogen production, transition metal selenides exhibit excellent electron transport properties and multiphase structures with varying conductivities. However, their widespread commercial application is hindered by sluggish reaction kinetics, a lack of exposed active sites, and significant volume expansion. Cobalt, a typical transition metal element abundantly found in the Earth's crust, offers sustainability and cost-effectiveness when used as an electrode material. In this work, a series of iron-modified carbon-supported cobalt selenides exhibit excellent catalytic performance in oxygen evolution reaction (OER) testing. Among them, CS/2XC-Fe@2 demonstrates outstanding activity for the oxygen evolution reaction in 1 M KOH, achieving a current density of 10 mA cm at a low overpotential of 261.8 mV. Additionally, density functional theory (DFT) calculations further revealed that the Fe interface with catalytic sites enhances electron transfer capabilities, as evidenced by density of states and charge analysis, which facilitates the intermediate reactions during electrocatalysis by reducing the energy barrier by 0.25 eV. This study contributes to advancing theoretical calculations and structure-activity relationship research on transition metal selenides, potentially offering a pathway for the large-scale synthesis of non-noble metal electrocatalysts.