Electronic modulation of multi-element transition metal phosphide by V-doping for high-efficiency and pH-universal hydrogen evolution reaction

Developing highly efficient, durable and noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) in a wide pH range is the key to achieve sustainable energy cycle. Modulating the electronic characteristics of catalysts is of great important to enhance their electrocatalytic performance. Herein, we successfully design a self-supported multi-element transition metal phosphide (V-CoP/Ni2P/NF) electrocatalyst by V-doping and interface engineering. According to DFT calculations, V dopants and the synergistic effect between CoP and Ni2P can bring optimal hydrogen/water adsorption free energies. Meanwhile, the 3D cross-linked network structure could expose abundant active sites and facilitate ions diffusion/electron transfer. As a result, the V-CoP/Ni2P/NF catalysts exhibit superior electrocatalytic activities with extremely low overpotentials of 20, 58 and 79 mV to deliver a current density of 10 mA cm−2 for HER in alkaline, neutral and acidic electrolytes, respectively. Moreover, they also display outstanding long-term stability. This electronic modulation strategy provides a promising pathway for energy-related catalysis processes.