Microwave shock motivating the Sr substitution of 2D porous GdFeO3 perovskite for highly active oxygen evolution

Abstract

The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity. Conventional methods for A-site substitution typically involve prolonged high-temperature processes. While these processes promote the development of unique nanostructures with highly exposed active sites, they often result in the uncontrolled configuration of introduced elements. Herein, we present a novel approach for synthesizing two-dimensional (2D) porous GdFeO₃ perovskite with A-site strontium (Sr) substitution utilizing microwave shock method. This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step, capitalizing on the advantages of rapid heating and cooling (temperature ∼1100 K, rate ∼70 K s⁻¹). The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure. For electrocatalytic oxygen evolution reaction application, the synthesized 2D porous Gd_0.8Sr_0.2FeO₃ electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm⁻² and a small Tafel slope of 55.85 mV dec⁻¹ in alkaline electrolytes. This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.