Preparation of selenium doped CuCoO₂ nanosheets as an efficient electrocatalyst for the oxygen evolution reaction

Hydrogen is a renewable clean energy source that is expected to replace traditional fossil fuels. The key technology for producing hydrogen from electrolyzing water depends on the efficiency and cost of high-performance catalyst materials. Electrocatalysts aim to accelerate the oxygen evolution reaction (OER) by reducing the reaction activation energy, which is the core element in improving the efficiency of water splitting. Among them, ion doping is an effective means of performance optimization. It introduces heteroatoms into the material lattice, changes the local coordination structure, and then adjusts the electronic structure to improve the catalytic performance. In this work, we have prepared nano-sized CuCoO₂ nanosheets with different Se dopant concentrations of 0.10, 0.30, and 0.50 mmol using a one-step solvothermal method. After optimization, the CCOSe-3 (0.30 mmol of Se dopant) sample exhibited an overpotential of 323 mV at 10 mA cm^-2 and a Tafel slope of 104.14 mV dec^-1 in 1.0 M KOH at room temperature. Furthermore, after an 18-hour OER stability test, the CCOSe-3 sample exhibited a negligible overpotential increase of 10 mV. This work may offer a novel insight into enhancing the OER activity of CuCoO₂ catalysts through nonmetallic element doping.