Gd1-xFeO3 perovskite oxides for catalyzing oxygen evolution reaction via A-site cation deficiency in alkaline media

Abstract

The main goal of this study is the development of nonprecious, highly effective, stable electrocatalysts for oxygen evolution reaction. In this work, we utilize a strategy to regulate the surface and structure of catalysts to boost the electrocatalytic activity and stability through A-site deficiency of Gd1-xFeO3 perovskites. We fabricated a novel perovskite structure with a nominal composition of Gd1-xFeO3 (0.0 ≤ x ≤ 0.15) using a facile sol-gel method. The XRD analysis proves the existence of a single phase up to x = 0.1. The deficit of Gd in the crystalline structure favors the morphology with smaller aggregated and more pores with grain sizes ranging from 224 to 251 nm. The Gd0.95FeO3 catalyst shows excellent OER catalytic activity with an overpotential 413 mV at 10 mA.cm−2, attributed to the higher surface area (4.19 m2/g) and the amount of the high oxidative oxygen species (O2−/O−). It also exhibits a low Tafel slope (88 mV.dec−1) and a large electrochemical surface area (65.5), a low charge transfer resistance (103 Ω) and good durability for 8 h in practical operation. These remarkable electrochemical characteristics of Gd0.95FeO3 distinguish it as a suitable electrocatalyst for future water-splitting applications.