A one-step synthesis of hierarchical porous CoFe-layered double hydroxide nanosheets with optimized composition for enhanced oxygen evolution electrocatalysis

Abstract

Hierarchical porous CoFe-LDHs composed of ultrathin nanosheets were successfully prepared by a simple one-step precipitation process of Co²⁺ and Fe³⁺ ions, avoiding multiple tedious steps. The optimized composition and the hierarchical porous structure design of the CoFe-LDHs endow them with high activity for OER in alkaline media (1 M KOH). Benefiting from the synergistic catalytic effects of the controllable composition and the structural features of CoFe-LDHs, the superior OER performance of hierarchical porous Co₈Fe₁-LDH nanosheets with optimal composition is achieved with the smallest overpotential (262 mV at 10 mA cm⁻²), lowest Tafel slope (42 mV per decade), and excellent long-term stability, which is superior to previously reported LDH-derived and commercial iridium dioxide (IrO₂) electrocatalysts, suggesting its promising application as an efficient electrode for OER.