Accelerated oxygen evolution kinetics on Ir-doped SrTiO₃ perovskite by NH₃ plasma treatment

Exploring low-cost and high-performance catalysts for oxygen evolution reaction (OER) remains to be a great challenge. Iridium-based perovskite oxide has large potential in OER because of its intrinsic activity and outstanding physicochemical properties. In this study, iridium-doped strontium titanate (Ir-STO) solution is brushed on a Ti sheet by the traditional method to obtain the Ir-STO/Ti electrodes after being calcined at a high temperature. The microstructure and electrocatalysis properties of the Ir-STO are further modified by a facile and scalable NH₃-plasma strategy. In addition to the doping of Ir, the NH₃ plasma treatment further results in N-doping into Ir-STO, which enriches active species and causes oxygen vacancies near doped sites. The resulting N, Ir-STO/Ti electrode reveals excellent acidic OER activity with the lowest overpotential of 390 mV at 10 mA/cm² and the smallest Tafel slope of 140 mV/dec after 10-min plasma treatment. Therefore, the great potential of activated N, Ir-STO/Ti is regarded as a catalyst for the OER, and thus making a new opportunity for developing other perovskite catalysts via NH₃ plasma treatment.