Ionic-liquid mediated synthesis of molybdenum disulfide/graphene composites: An enhanced electrochemical hydrogen evolution catalyst

Abstract The ionic liquid (IL, [BMIM]BF 4 ) is employed to mediate the preparation of molybdenum disulfide/graphene composites by hydrothermal route in the presence of graphene oxide sheets. The effects of ionic liquid on the microstructure and hydrogen evolution reaction performances of molybdenum disulfide/graphene are investigated. The molybdenum disulfide/graphene composite (MoS 2 /G-IL10) prepared with 1.0 mL of ionic liquid displays numerous de-layered molybdenum disulfide sheets with short slab length and discontinuous crystal fringes on the surface of grapheme. Due to the rich exposed edge sites, as well as the synergetic effect of de-layered molybdenum disulfide and graphene sheets, the MoS 2 /graphene composite prepared by IL-mediated hydrothermal method shows excellent electrocatalytic performance for hydrogen evolution reaction with a small Tafel slope of 52 mV/dec in acidic medium.