Phosphate ion functionalized Ni(OH)2/Ni/MoO2 composite for enhanced alkaline hydrogen evolution.

The development of efficient electrocatalysts for hydrogen evolution reaction (HER) is important in advancing sustainable energy technologies. This work introduces a phosphate ion modified Ni(OH)₂/Ni/MoO₂ (PNNM) composite, elaborately constructed by a one-pot electrodeposition method. The integration of heterostructure engineering and ion modification strategies significantly endows the composite with remarkable electrocatalytic performance. The prepared PNNM has excellent HER activity, with a low overpotential of 35 mV to achieve a current density of 10 mA cm^-2 and a favorable Tafel slope of 59.5 mV dec^-1. Meanwhile, PNNM also possesses prominently long-term durability with the current density retention rate of 90.1 % after 240 h. In-situ Raman, electrochemical analysis, and theoretical calculation results reveal that the enhanced HER activity of PNNM results from the moderated hydrogen adsorption strength, robust water adsorption, and accelerated water dissociation process. This study highlights the potential of PNNM as a promising candidate for scalable alkaline hydrogen generation, offering significant advancements in renewable energy applications.