Engineering Oxygen Vacancies into LaCoO 3 Perovskite for Efficient Electrocatalytic Oxygen Evolution

Oxygen vacancies (OVs) can improve catalytic activities in oxygen evolution reaction (OER). Although considerable effort has been devoted to increasing the OVs concentration in electrocatalysts, limited OVs have been created by current techniques so far. Here, we, for the first time, engineered (i.e., created) abundant OVs into perovskites by element doping and plasma treatment. The results revealed that more OVs were manufactured by combination of Sr doping with Ar plasma treatment, leading to improved OER activity and high stability of LaCoO 3 perovskite. The La 1- x Sr x CoO 3-δ ( x = 0.3) sample with Ar plasma treatment (denoted as Sr-0.3-p) showed high OER activity and stability due to the existence of rich OVs, which provided large amounts as well as high intrinsic activity of active sites in OER. The combination of two OV-creating techniques provides an efficient strategy to develop OV-rich catalysts for various applications.