Construction of reduced graphene oxide coupled with CoSe2-MoSe2 heterostructure for enhanced electrocatalytic hydrogen production.

Abstract 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 CoSe2-MoSe2 heterostructure grown on reduced graphene oxide with an optimum Co/Mo proportion of 1:1 (CoSe2-MoSe2(1–1)/rGO). It exhibits good HER activities in both acidic and alkaline conditions. The CoSe2-MoSe2(1–1)/rGO shows an overpotential of 107 mV at 10 mA cm−2 with a Tafel slope of 56 mV dec−1 under acidic condition. Meanwhile, CoSe2-MoSe2(1–1)/rGO also presents an overpotential of 182 mV at 10 mA cm−2 and with a Tafel slope of 89 mV dec−1 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 CoSe2-MoSe2 heterostructure as well as the optimized hydrogen adsorption energy of CoSe2-MoSe2 interface. The design of CoSe2-MoSe2(1–1)/rGO provides a meaningful guide for manufacturing electrode in energy storage and conversion.