Boosted Electrochemical\nHydrogen Evolution Activity\nvia the Core–Shell Heterostructure of Nickel Sulfide Nanoframe-Supported\nLayered Rhenium Disulfide

The strategic design of a heterostructure catalyst with\na core–shell\nnanoarchitecture is imperative for enhancing the efficiency of the\nelectrocatalytic hydrogen evolution reaction (HER). Herein, the core–shell\ncatalyst comprising the rhenium disulfide nanosheets was vertically\nintegrated onto a hollow nickel sulfide (NiS@ReS<sub>2</sub>) via\ncoprecipitation and hydrothermal treatment. The morphology involves\nthe sulfurization of a nickel-based Prussian blue analogue, effectively\nmitigating the aggregation of ReS<sub>2</sub> nanosheets and maximizing\nthe exposed active sites. By the synergistic effect of morphological\ndesign and heterostructure formation, the overpotential of NiS@ReS<sub>2</sub> is 136 mV at 10 mA cm<sup>–2</sup> in an alkaline\nelectrolyte, and the rapid kinetics is confirmed by the small Tafel\nslope and low charge transfer resistance during the HER process. Moreover,\nthe electrocatalytic durability of NiS@ReS<sub>2</sub> is elucidated,\nand the boosted catalytic activity of NiS@ReS<sub>2</sub> is confirmed\nby density functional theory. This study unveils a promising method\nfor advancing ReS<sub>2</sub>-based electrocatalysts with potential\nimplications for producing hydrogen.