One-Step Hydrothermal Fabrication of Three-dimensional MoS2 Nanoflower using Polypyrrole as Template for Efficient Hydrogen Evolution Reaction

Herein, a facile and cost-effective strategy for hydrothermal synthesis of three-dimensional (3D) MoS2 with adequate active edge sites and advanced hydrogen evolution reaction (HER) performance using polypyrrole (PPy) as template is reported. The MoS2 is first thermally nucleated using hexaammonium heptamolybdate tetrahydrate (NH4)6Mo7O24·4H2O and thiourea as precursor in the presence of PPy, and then they are further annealed to remove PPy at higher temperature to generate 3D MoS2-P. Morphology and composition characterizations reveal that the 3D MoS2-P exhibits a nanoflower morphology. It presents larger stretched "thin folding leaves" and higher mesoporous volume of 0.608 cm3 g-1 than the MoS2 without PPy as template. Importantly, the 3D MoS2-P shows enhanced HER catalytic activity (onset potential at -100 mV) than previously reports that MoS2-based HER catalysts. The large "thin folding leaves" possessing efficient edge active sites and defects are responsible to for the enhanced HER performance, while the high mesoporous volume facilitates the transfer of reaction substrate. Our study provides a facile and cost-effective method for synthesis of 3D MoS2 with advanced HER performances, which has great potential for larger-scale production and practical industrial applications.