CoFePS Quaternary Alloy Sub‐Nanometric Sheets by Synchronously Phospho‐Sulfurizing CoFe‐Bimetallene for Boosting Oxygen Evolution Reaction

Abstract Due to the sluggish kinetics of oxygen evolution reaction (OER), electrocatalysts are urgently needed to simultaneously achieve increased activity, enhanced stability, and reduced cost. Herein, CoFePS quaternary alloy sub‐nanometric sheet is synthesized via synchronously phosphor‐sulfurizing CoFe‐bimetallene. Heteroatomization results in increasing conductivity, enhancing interactions with electrolyte, and improving chemical structural stability to exhibit a current density of 10 mA cm⁻² at 211 mV and a large current of 1053 mA cm⁻² at 570 mV. Density functional theory calculations reveal that the adjustment of Fermi levels of adjacent metal atoms reduces reaction energy barrier and accelerates electron transfer, resulting in a Tafel slope of 14 mV dec⁻¹. In situ Raman monitors the formation of phosphor‐sulfate shell oxidized surface as active sites improved the OER stability of CoFePS, with a retention rate of 99.7% at 10 mA cm⁻² for 78 h. This study provides a promising strategy for the synthesis of multicomponent alloy sub‐nanometric sheet as good electrocatalyst candidates for OER.