Se-doped cobalt oxide nanoparticle as highly-efficient electrocatalyst for oxygen evolution reaction

Electrolysis of water has been one of the most promising approaches for renewable energy resources while the efficient oxygen evolution reaction (OER) remains challenging. Herein, a series of different ratio of Se doped Co3O4 nanoparticles XSe-Co3O4 are prepared by hydrothermal method and applied as OER electrocatalysts. Se2− is doped into the Co3O4 crystal lattice by substituting of O2− and a large number of oxygen vacancies are generated, which provides more available activity sites for OER. Se doping increases the surface ratio of Co2+/Co3+ and accelerates the electron transport that favors OER activity promotion. The optimized doping ratio of 6%Se–Co3O4 presents low overpotential of 281 mV at 10 mA cm−2, as well as a low Tafel slope of 70 mV dec−1 in 1 M KOH solution, which has great advantages compared to the recently reported Co3O4-based OER electrocatalysts. This work provides new ideas for the development of efficient Co3O4-based OER electrocatalysts.