Dual‐Engineered Electrocatalyst: Work‐Function‐Driven Electronic Reconfiguration and Self‐Sacrifice Nanorod‐Templated Nanoflowers of Ni 3 S 2 /MoS 2 Heterojunctions for High‐Performance Hydrogen Evolution

ABSTRACT Water electrolysis is a promising method for green hydrogen production, but slow hydrogen evolution reaction (HER) kinetics require efficient catalysts. In this study, we develop a Ni 3 S 2 /MoS 2 heterostructure electrocatalyst using a work‐function‐driven electronic modulation strategy combined with a self‐sacrificial template approach. Density functional theory (DFT) calculations show that the work function difference between Ni 3 S 2 and MoS 2 induces electron transfer at the interface, creating an electric field that enhances charge transport and optimizes the adsorption of key intermediates. This reduces the energy barrier for O–H bond cleavage and tunes the hydrogen adsorption free energy close to ideal values. The Ni 3 S 2 /MoS 2 @NF–MO catalyst achieves a low overpotential of 67 mV at 10 mA cm −2 and demonstrates excellent stability over 100 h. In situ electrochemical impedance spectroscopy confirms improved charge transfer, boosting HER activity. These results provide a new design strategy for alkaline HER electrocatalysts, offering valuable guidance for the development of green hydrogen production technologies.