Modulating the oxygen evolution reaction activity of SrIrO3/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 catalysts using electric-field polarization

Abstract

The physical properties of epitaxially grown SrIrO₃ thin films are sensitive to external influences. This provides a rare opportunity to study their physical properties as regulated by electric-field polarization of their substrates, thus affecting their oxygen evolution reaction activity. In this work, SrIrO₃ films were epitaxially grown on (001)-oriented Pb(Mg_1/3Nb_2/3)_0.7Ti_0.3O₃ (PMNPT) single-crystal substrates by pulsed laser deposition. After applying an electric field to the PMNPT along the [001] direction, a lattice strain is induced by rotation of its ferroelectric domains, and this lattice strain is transferred to the interior of the SrIrO₃ film through the epitaxial interface. This changes the surface resistivity of the SrIrO₃ film and affects its electrocatalytic activity. Our findings suggest that substrate polarization is a feasible method for regulating the electrocatalytic performance of SrIrO₃ thin films, and this provides new inspiration for the structural design of other composite catalysts.