Synergistic effects of fluorine doping on CoPS electrocatalysts for highly efficient hydrogen evolution reaction†

Exploring earth-abundant electrocatalysts for efficient hydrogen evolution reaction (HER) is important for the development of clean and renewable hydrogen energy. Herein, we demonstrated that fluorine anion doping into CoPS significantly enhanced its hydrogen evolution reaction (HER) activity. Controlled fluorination modulated the surface electronic structure of CoPS active sites, forming an optimized F-CoPS electrocatalyst that exhibited superior performance, achieving an overpotential of only 74 mV at 10 mA cm⁻² and 141 mV at 50 mA cm⁻², along with remarkable stability over 50 hours. This study provides a novel and feasible approach to enhance the HER performance of ternary pyrite-type transition-metal phosphosulfides.