Anchoring acetylene black on graphene for growing of molybdenum disulfide as high performance electrocatalysts in hydrogen evolution reaction

A series of Molybdenum sulfide/acetylene black-reduced graphene oxide composites (MoSx/AB-rGO) was prepared by a facile one-step solvothermal method. The morphology characterizations confirmed that the presence of AB could effectively prevent the reduced graphene oxide (rGO) from restacking in the solvothermal process, providing the abundant anchoring area for the MoS2 generated during the solvothermal process. For the as prepared MoS2/AB-rGO catalysts, a large number of amorphous molybdenum sulfide (a-MoS2) on the surface of rGO and low-crystallization molybdenum sulfide (1c-MoS2) on the surface of AB provide sufficient active sites for hydrogen evolution reaction (HER). HER tests of MoS2/AB-rGO proved that the dual function of AB, both augmenting the active sites and elevating the conductivity, could be a well-founded account for its excellent HER activity. In contrast, MoS2/rGO synthesized without AB showed severe agglomeration and poor internal conductivity on account of interlamellar van der Waals’s force. MoS2/AB-rGO(55) exhibits high HER performance including a low onset potential (−100 mV) and a large current density (10.0 mA/cm2 at η = 142 mV), indicating it is a promising electrocatalyst for HER.