Application of Sm0.8Sr0.2Fe1-xCoxO3-δ (x = 0.2, 0.5, 0.8) perovskite for the oxygen evolution reaction in alkaline media

Abstract

A new type of perovskite, i.e. Sm0.8Sr0.2Fe0.8Co0.2O3-δ (SSFC1), Sm0.8Sr0.2Fe0.5Co0.5O3-δ (SSFC2), and Sm0.8Sr0.2Fe0.2Co0.8O3-δ (SSFC3) were (i) synthesised by employing a sol gel method with subsequent calcination at 1000 °C for 10 h and (ii) investigated for its activity towards the oxygen evolution reaction (OER) in alkaline medium. The synthesised perovskites were examined by X-ray diffraction to determine the crystal structure of the material while the textural properties were examined by Fourier transform infrared spectroscopy (FTIR). The morphology and microstructure were examined by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The SSFC2 perovskite exhibited the highest catalytic activity, with a Tafel slope of 112 mV and an overpotential (η) of 0.400 V (V vs. RHE) to achieve 10 mA cm−2, as well as good stability in 0.1 M KOH in that it only showed an increase of 40 mV over a 2-h potentiodynamic scan. These SSFCn (n = 1, 2, or 3) perovskites exhibit extreme flexibility in their composition and allows for a simple approach in doping to enhance their activity for the OER, which make them good candidates for the OER in alkaline solution