Epitaxial Strain Dependent Electrocatalytic Activity In Caruo3 Thin Films

The systematic tunability of electrocatalytic activity is indispensable not only for realizing highly efficient catalysts but also for understanding the underlying mechanism of chemical reactions at the surface. Epitaxial strain is a powerful tool for tailoring various physical and chemical properties of perovskite transition metal oxides, including electrocatalytic activity. We present single-crystalline CaRuO3 epitaxial thin films as a model system, in which the oxygen evolution reaction was systematically controlled by the epitaxial strain. With an increase in the degree of tensile strain, the interband transition energy and hybridization strength within the Ru-O bond decreased, which enhanced the oxygen evolution reaction. Our study facilitates the understanding of the correlation between the lattice/electronic structure and the electrocatalytic activity, which might be applied to other transition metal oxide catalysts. Published under license by AIP Publishing. https://doi.org/10.1063/5.0020934