Tuning the surface chemistry of La0.6Sr0.4CoO3-δ perovskite via in-situ anchored chemical bonds for enhanced overall water splitting

Abstract

Perovskites have garnered huge interest as electrocatalysts in water–oxidation. Despite their salient features, chemical instability of the perovskite oxide surfaces still limits their durability in electrochemical water–splitting. Here, we propose a simple strategy to increase the overall activity and stability of La0.6Sr0.4CoO3-δ (LSC) perovskite just by reconstructing its surface. Preeminent oxygen evolution (OER) and hydrogen evolution reaction (HER) catalysts, namely, nickel–iron oxyhydroxide (NiFe(OH)2 denoted as NiFe) and nickel–manganese hydroxide (NiMn(OH)2 denoted as NiMn) are in–situ anchored on LSC surface, respectively. The resulting composites greatly facilitate the electron mobility and deliver excellent activity towards OER and HER with low overpotentials of η = 250 mV at 10 mA cm−2 and η = 63 mV at 50 mA cm−2, respectively. The (LSC@NiFe‖LSC@NiMn) electrolyzer reached 10 mA cm−2 at a cell voltage of 1.57 V. We also validated the redistribution of electrons and oxygen, and the abundance of exposed active sites by incorporation of active hydroxides.