Vertical V-Doped CoP Nanowall Arrays as a Highly Efficient and Stable Electrocatalyst for the Hydrogen Evolution Reaction at all pH Values

Developing low-cost and high-efficiency electrocatalysts toward hydrogen evolution reaction (HER) in a wide pH range is still challenging. Herein, a three-dimensional (3D) porous nanoarchitecture, constructed by vertical V-doped CoP nanowall arrays (V-CPNA), has been grown on carbon cloth (CC) via a simple liquid-reaction approach and subsequent phosphorization. As a binder-free electrocatalyst, the V-CPNA/CC exhibits outstanding HER activity in the entire pH range. Particularly, it shows ultralow overpotentials of 87, 93, and 98 mV at 10 mA cm(-2) in alkaline, acidic, and neutral media, respectively. Moreover, it delivers outstanding electrochemical durability with no degradation up to 60 h at all pH values. Such excellent electrocatalytic performance is mainly attributed to the synergistic effect between V and Co atoms. In addition, the unique 3D nanostructure of V-doped CoP nanowall arrays can promote the diffusions of H-2 gas and the access of electrolytes, thus boosting the HER performance. This work presents a facile strategy to synthesize 3D porous heteroatom-doped metal phosphides as highly effective and stable pH-universal catalysts for HER.