Synergistic effect of cocatalytic NiSe 2 on stable 1T-MoS 2 for hydrogen evolution.

Robust and economical catalysts are imperative to realize the versatile applications of hydrogen. Herein, a 1T-MoS 2 /N-doped NiSe 2 composite was rationally synthesized via a solvothermal method, in which the MoS 2 nanosheets have a stable 1T phase structure, and the NiSe 2 nanoparticles serve as a cocatalytic support for MoS 2 . The nonnegligible electronic couplings between NiSe 2 and MoS 2 could facilitate the optimization of their electronic structure and then improve the hydrogen adsorption. What is more, the nitrogen dopants in the NiSe 2 nanoparticles could intensify the intercalation of ammonium ions in the 1T-MoS 2 nanosheets, and further enlarge their interlayer spacing, thus the electrolyte could infiltrate into the catalyst more easily and sufficiently. This work provides a new route for rationally designing highly active and low cost hydrogen evolution reaction (HER) catalysts, and enriches the study of transition metal chalcogenides toward HER.