One-Step Synthesis of 1T MoS₂ Hierarchical Nanospheres for Electrocatalytic Hydrogen Evolution

Two-dimensional transition-metal dichalcogenides are affordable alternatives to noble metal catalysts for hydrogen evolution reaction (HER). Here, we report a facile one-step solvothermal method to synthesize the 1T MoS2 hierarchical nanosphere (NSP) that can function as an efficient and stable electrocatalyst for HER using an environment-friendly solvent without the assistance of a template or additive. The reaction solvent is found to play a vital role in regulating the morphology and phase of the resultant MoS2. A haystack of 2H MoS2 nanosheets is obtained when water is used as the solvent, and the 1T MoS2 NSP is attained when ethanol is used. The 1T MoS2 NSP has a three-dimensional hierarchical structure and good conductivity, which lead to the excellent electrocatalytic HER performance in an acid solution with its overpotential lower than the reported MoS2-based electrocatalysts. It also demonstrates exceptional electrochemical stability, showing little variation in overpotential for 5000 reaction cycles.