A facile top-down approach for constructing perovskite oxide nanostructure with abundant oxygen defects as highly efficient water oxidation electrocatalyst

Developing highly efficient electrocatalysts for oxygen evolution reaction (OER) is of sig-nificant importance for the application of many energy conversion and storage technolo-gies. Perovskite oxides have attracted great attention as potential OER electro-catalysts. Their performance, however, are strongly limited by large particle size, owing to the high synthesis temperature. Herein, we report a facile top-down strategy for fabricating perovskite oxide nanostructures with large surface area and strongly improved intrinsic OER activity. SrNb0.1Co0.7Fe0.2O3-delta (SNCF) particles with micro size are treated by (NH4)(2)-Fe(SO4)(2) saturated solution for different time length at room temperature. The obtained catalysts exhibit significantly increased surface area with nanosheet structure in the outer layer. Furthermore, cobalt on the surface are reduced from Co3+ to Co2+, suggesting oxygen vacancy formation on the surface. The defective SNCF nanostructure exhibits significantly improved OER activity and good stability. The facile methodology reported in this work can be generally applied to other oxide electrocatalysts for energy applications. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.