Electronic structure regulation of CoP nanorods by tunable incorporation of oxygen for enhanced electrocatalytic activity toward hydrogen evolution reaction

Exploration of cost-effective and high-efficient electrocatalysts for hydrogen evolution reaction (HER) is of great significance for realizing sustainable H2 production. As proposed, anion incorporation in earth-abundant promising transition metal-based electrocatalysts could be a reasonable and competitive approach to regulate the electronic structure with optimized atomic hydrogen adsorption and desorption for enhanced intrinsic electrocatalytic performance of HER. Herein, we present a rational design and fabrication of O-incorporated CoP (expressed as O-CoP) nanorods with controllable component and electronic structure. As demonstrated, when the lattice-incorporated O in an appropriate concentration, the engineered O-CoP nanocatalysts have more active sites exposed with increased electrochemical active areas and better electron/ion conductivity, leading to boosted HER activity and running stability. Typically, the obtained O-CoP nanorods with optimal oxygen content exhibit the excellent HER activity with an overpotential of 116 mV at the current density of 10 mA cm-2, and a small Tafel slope of 59 mV dec-1 in alkaline media. The anion doping strategy may have widespread contributions for efficient engineering of electrocatalysts in energy conversion devices.