Assembled 3D electrocatalysts for efficient hydrogen evolution: WSe2 layers anchored on graphene sheets

A new 3D composite electrocatalytic material is produced by growing WSe2 thin layers vertically on 2D reduced graphene oxide nanosheets. The material has improved electrode/electrolyte interactions and efficient catalytic properties due to the rich defects, a 3D hybrid configuration, and the direct integration of WSe2 onto the graphene sheets, which can significantly prevent the aggregation of WSe2 and promote the conductivity of the material. As demonstrated, the as-harvested WSe2/graphene hybrid exhibits excellent electrocatalytic activity in the hydrogen evolution reaction (HER), such as a low onset over-potential of -100 mV, a small Tafel slope of 64 mV per decade and outstanding stability.