Highly efficient and stable electrocatalyst for hydrogen evolution by molybdenum doped Ni-Co phosphide nanoneedles at high current density

There is an increasingly urgent need to develop cost-effective electrocatalysts with high catalytic activity and stability as alternatives to the traditional Pt/C in catalysts in water electrolysis. In this study, microspheres composed of Mo-doped NiCoP nanoneedles supported on nickel foam were prepared to address this challenge. The results show that the nanoneedles provide sufficient active sites for efficient electron transfer; the small-sized effect and the micro-scale roughness enhance the entry of reactants and the release of hydrogen bubbles; the Mo doping effectively improves the electrocatalytic performance of NiCoP in alkaline media. The catalyst exhibits low hydrogen evolution overpotentials of 38.5 and 217.5 mV at a current density of 10 mA center dot cm(-2) and high current density of 500 mA center dot cm(-2), respectively, and only 1.978 V is required to achieve a current density of 1000 mA center dot cm(-2) for overall water splitting. Density functional theory (DFT) calculations show that the improved hydrogen evolution performance can be explained as a result of the Mo doping, which serves to reduce the interaction between NiCoP and intermediates, optimize the Gibbs free energy of hydrogen adsorption (Delta G(*H)), and accelerate the desorption rate of *OH This study provides a promising solution to the ongoing challenge of designing efficient electrocatalysts for high-current-density hydrogen production.

Automated summary

This study developed Mo-doped NiCoP nanoneedles supported on nickel foam, which provide a promising solution to the urgent need for cost-effective electrocatalysts with high catalytic activity and stability in water electrolysis. The nanoneedles offer sufficient active sites for efficient electron transfer, while the Mo doping enhances the electrocatalytic performance of NiCoP. The catalyst exhibits low hydrogen evolution overpotentials and only requires a low voltage for overall water splitting.