Dandelion-like V–CoP nanoarchitectures derived from MOFs: boosting the HER via enhanced water dissociation at industrial current densities

Abstract

To address the sluggish kinetics and limited current density in the alkaline hydrogen evolution reaction (HER), we designed and synthesized dandelion-like V-doped CoP anchored on carbon cloth (V–CoP-X) via a MOF-derived strategy involving hydrothermal growth and subsequent phosphidation. By precisely controlling the V content in the MOF precursor, we achieve tunable morphologies of V–CoP materials. Experimental analyses reveal that Lewis acid sites of V promote electron transfer and adjust the d-band centers of V–CoP. According to the results of experimental and density functional theory (DFT) calculations, the V-doped CoP lowers the water dissociation energy in alkaline media and optimizes the adsorption energy for H* (ΔG_H*). These synergistic effects accelerate water dissociation kinetics as well as optimize adsorption and desorption behavior of H*, leading to improved HER activity in 1 M KOH and 0.5 M H₂SO₄. As a result, the optimal V–CoP electrode exhibits exceptional HER performance in diverse electrolytes, requiring low overpotentials of 69, 63 and 89 mV to obtain 10 mA cm⁻² as well as 212, 254 and 401 mV at 500 mA cm⁻² in 1 M KOH, 1 M KOH + 0.5 M NaCl and 0.5 M H₂SO₄, respectively. Remarkably, V-doped CoP possesses excellent long-term stability at large current density. This work presents a high-performance HER electrocatalyst while providing fundamental insights into the role of V doping in enhancing reaction kinetics.