Tri-metallic fluoride nanoplates immobilized on reduced graphene architectures as efficient oxygen evolution reaction catalyst

Exploring the transition metal fluoride-based catalysts with highly catalytic activity is of great importance to satisfy the electrochemical oxygen evolution reaction (OER). Herein, the tri-metallic (cobalt, iron, and nickel) fluorides immobilizing on reduced graphene oxide architectures (CoFeNiF-rGAs) are constructed by hydrothermal and low-temperature fluoridation. The hierarchical structure assembled by the π-π configuration of graphene can provide abundant channels for fast ion diffusion and guarantee the uniform loading of metal fluorides. Owing to the hierarchical morphology and the formation of metal fluorides/graphene interfaces, CoFeNiF-rGAs can show excellent OER performance. Only 238 mV of overpotential is required to achieve a current density of 10 mA cm⁻² in alkaline electrolyte, and the Tafel slope (78.8 mV dec^-1) and charge transfer resistance (13.6 Ω) are smaller than the control samples, respectively, implying a fast kinetic behavior during OER. The highly catalytic stability of CoFeNiF-rGAs is confirmed by 1000 cyclic voltammetry and chronoamperometry test for 20 h, and the boosted catalytic mechanism is elucidated by density function theory calculation.