▎ 摘　　要

Driven by the demands of environmental protection and seeking renewable energy sources, developing nonprecious-metal based electrocatalysts with preeminent activity and stability for the hydrogen evolution reactions (HER) has received intensive attention, but it still remains a great challenge. Here we demonstrate defects on reduction graphene oxide (rGO) not only can serve as nucleation sites for uniform CoP nanoparticle growth, but also generate more isolated electrons, significantly changing the local charge state of P around the defects and leading to an optimized Gibbs free energy of H adsorption. The CoP nanoparticles adsorbed on the defects of reduction graphene oxide (CoP@DrGO) showed remarkable electrocatalytic activity toward the HER in the base solution with an overpotential of 36.6 mV at 10 mA cm(-2) and a Tafel slope of 43.1 mV dec(-1), which are not only superior to most of other CoP-based materials reported previously but also comparable to the commercial Pt/C catalyst. This work not only provides a highly efficient, low-cost and stable electrocatalyst for HER, but also offers a new way of designing high-performance electrocatalysts.