Ni-Mo-S Ternary Chalcogenide Thin Film for Enhanced Hydrogen Evolution Reaction

Transition metal dichalcogenides (TMDs) hold a great promise to replace Pt-based catalysts for hydrogen evolution reaction (HER). Among those, MoS2 has been the center of attention. In this work, we investigate the effect of Ni addition on the catalytic activity of MoS2 thin film in HER. Ni-Mo-S ternary chalcogenide thin films with varying Ni concentrations were fabricated by a two-step process: co-sputtering of Ni-Mo alloy films and thermal sulfurization. The HER performance of MoS2 (620 mV overpotential and 138 mV dec(-1) Tafel slope) is surpassed by the resulting ternary chalcogenides, among which the Ni-Mo-S film at 50 at.% Ni concentration exhibits the highest catalytic activity with an overpotential of 400 mV at 10 mA cm(-2) and Tafel slope of 81 mV dec(-1). The Ni addition promotes HER kinetics by altering the morphology and electronic structure of MoS2 thin film, leading to improved H+ ion adsorption, reduced charge transfer resistance and increased electrochemical surface area. This study provides a method for the controllable fabrication of ternary chalcogenide thin films and paves the way for the exploration of new combinations of ternary TMDs. [GRAPHICS] .