Microwave Shock Process for Rapid Synthesis of 2D Porous La0.2Sr0.8CoO3 Perovskite As an Efficient Oxygen Evolution Reaction Catalyst

The oxygen evolution reaction (OER) is considered the rate-limiting step in electrochemical water splitting, and has been widely used to solve energy and environmental issues. Perovskite oxides (ABO3) exhibit good OER activity, owing to their tunable electronic structures and highly flexible elemental compositions. However, the preparation of perovskite oxides usually requires long exposure to high temperatures, resulting in metal agglomeration and undesirable effects on intrinsic activity. Vapor-phase microwave technology can significantly reduce the duration of heat treatment and subsequently reduce the associated carbon emissions. This technology not only addresses the growing demand for carbon-neutral processes but also enables increased control of the synthesis to avoid undesirable agglomeration of the product. In this study, a 2D porous La0.2Sr0.8CoO3 perovskite was rapidly prepared using a microwave shock method. The rapid entropy increase associated with the microwave process can effectively expose abundant active sites in the La0.2Sr0.8CoO3 structure. Furthermore, the high-energy microwave shock process can precisely introduce Sr2+ into the lattice of LaCoO3, increasing the number of oxygen vacancies by increasing the oxidation state of Co. The oxygen vacancies introduced by replacing La with Sr can considerably improve the intrinsic catalytic activity of the material. For the OER in alkaline electrolytes, the prepared La0.2Sr0.8CoO3 catalyst displayed an excellent overpotential of 360 mV at 10 mA center dot cm-2 and a Tafel slope of 76.6 mV center dot dec-1. After a long-term cycle test of 30000 s, 97% of the initial current density was maintained. This study presents a facile and rapid strategy for the synthesis of highly active 2D perovskites.