A Cake‐Style CoS2@MoS2/RGO Hybrid Catalyst for Efficient Hydrogen Evolution

A three‐tiered cake‐style composite is elaborately established, with the characteristic of a double‐deck of MoS 2 nanosheets and reduction of graphene oxide (RGO) sheets dotted with CoS 2 nanoparticles (CoS 2 @MoS 2 /RGO). Because of the prominent synergistic effect of graphene acting as conductive support, MoS 2 and CoS 2 providing abundant catalytically active sites, and the cake‐style structure promoting mechanical stability, the CoS 2 @MoS 2 /RGO exhibits a superior hydrogen evolution reaction activity with a small overpotential of 98 mV at cathodic current density of 10 mA cm −2 , and a small Tafel slope of 37.4 mV dec −1 , as well as excellent cycling stability. Density functional theory calculations reveal that the hydrogen adsorption free energy of CoS 2 @MoS 2 /RGO is close to zero.