Facile surface defect engineering on perovskite oxides for enhanced OER performance

Abstract

Perovskite oxides have been considered as potential alternative electrocatalysts in the oxygen evolution reaction (OER) field. In this work, a sequence of excellent OER perovskite catalysts was obtained by immersing Sr₂CoFeO₆ in a diluted HNO₃ solution. Therein, the 24 h etched Sr₂CoFeO₆ sample (SCFO-24) exhibits the best OER activity, with an overpotential of 300 mV at 10 mA cm⁻² and a Tafel slope of 59.62 mV dec⁻¹. The improved OER activity of SCFO-24 can be attributed to the enhanced specific surface area derived from selective dissolution of a large amount of Sr and the high ratio of oxidative oxygen species (O²⁻/O⁻). Our work promotes this simple but efficient approach to improving the OER performance of perovskite oxides.