Promoting Reactant Accumulation at Solid–Liquid Interfaces through Microstrain-Defect Engineering in Overall Water Splitting

Abstract

Water electrolysis is limited by interfacial mass transfer and ion interactions. Herein, a microstrain-engineered CoFePS was derived from CoFeLDH. The strategy enhanced the solid-liquid (S-L) junction, doubled the double-layer capacitance (Cdl), and improved ion diffusion as confirmed by operando Electrochemical Impedance Spectroscopy (EIS). The CoFePS catalyst achieved a cell potential of 1.44 V at 10 mA/cm² with over 200 hours of stability, demonstrating the critical role of surface reactant enrichment.