Solvothermal decoration of Cu3SnS4 on reduced graphene oxide for enhanced electrocatalytic hydrogen evolution reaction

Metal sulphides combined with graphene/reduced graphene oxide (rGO) represent a unique class of materials for hydrogen generation either through electrocatalytic or photo(electro) catalytic methods. Herein, we report a solvothermal synthesis of Cu3SnS4 decorated rGO resulting in a highly active electrocatalyst for hydrogen evolution reaction (HER) compared to its native Cu3SnS4. The Cu3SnS4-rGO exhibited very low overpotential of 190 mV versus reversible hydrogen electrode (RHE), whereas Cu3SnS4 requires 250 mV versus RHE at a current density of 10 mA/cm(2). Tafel slope of Cu3SnS4-rGO and Cu3SnS4 is about 64 and 76 mV/dec, respectively. This suggests that Cu3SnS4-rGO is a better electrocatalyst when compared to Cu3SnS4 and follows mixed Volmer and Heyrovsky mechanism for HER.