Construction of reduced graphene oxide coupled with CoSe-MoSe heterostructure for enhanced electrocatalytic hydrogen production.

It is important to develop novel energy to solve energy shortage and environmental problems. Hydrogen evolution reaction (HER) is envisaged as a viable technology that can be used to develop sustainable clean energy. Herein, we report a catalyst with CoSe-MoSe heterostructure grown on reduced graphene oxide with an optimum Co/Mo proportion of 1:1 (CoSe-MoSe(1-1)/rGO). It exhibits good HER activities in both acidic and alkaline conditions. The CoSe-MoSe(1-1)/rGO shows an overpotential of 107 mV at 10 mA cm with a Tafel slope of 56 mV dec under acidic condition. Meanwhile, CoSe-MoSe(1-1)/rGO also presents an overpotential of 182 mV at 10 mA cm and with a Tafel slope of 89 mV dec under alkaline condition. These impressive performances of the catalyst are mainly due to the excellent electronic transmission capability of rGO and the abundant active sites of CoSe-MoSe heterostructure as well as the optimized hydrogen adsorption energy of CoSe-MoSe interface. The design of CoSe-MoSe(1-1)/rGO provides a meaningful guide for manufacturing electrode in energy storage and conversion.