Graphene-Amorphous Transition-Metal Chalcogenide (MoSx, WSx) Composites as Highly Efficient Hybrid Electrocatalysts for the Hydrogen Evolution Reaction

Layered transition-metal dichalcogenides (TMDs) show promising electrocatalytic properties towards the hydrogen evolution reaction (HER). A series of graphene-amorphous TMD composites were prepared under hydrothermal conditions. Materials with varying contents of MoSx and WSx were synthesized from ammonium tetrathiomolybdate and ammonium tetrathiotungstate precursors in the presence of graphene oxide and diethylene glycol as a reducing agent. The synthesized materials exhibit not only a homogeneous distribution over the graphene surface, but also high electrocatalytic activity towards the HER. These findings are highly promising for industrial electrocatalysis, because the onset potential is close to the HER potential of industrially used platinum catalysts.