Regulation of the adsorption sites of Ni2P by Ru and S co-doping for ultra-efficient alkaline hydrogen evolution

Abstract

The development of alkaline hydrogen evolution catalysts is a demanding and highly desirable task to expand clean energy applications, but is hindered by the sluggish kinetics of alkaline electrochemical water splitting. In this work, we developed a metal–nonmetallic co-doping strategy to improve the active site number and boost the alkaline hydrogen evolution reaction (HER) kinetics of Ni₂P by optimizing the electronic environment to regulate the adsorption site. Owing to the synergistic effect of the co-doping of Ru and S, the optimized Ru/S–Ni₂P nanosheets required a low overpotential of only 49 mV to drive 10 mA cm⁻² for the HER, which was 132 mV lower than that of pure Ni₂P. A combined experimental and density functional theory (DFT) calculation study identified that Ru and S co-dopants could reform the electronic arrangement of Ni₂P to enhance charge transfer and optimize the water-adsorption energy and the H* adsorption energy for better HER activity. Such a co-doped strategy may provide opportunities for preparing efficient and stable alkaline HER electrocatalysts.