Electronic and optical properties and electrocatalytic water splitting in a graphene/MoS2 heterojunction

The electronic and optical properties of graphene/MoS2 heterojunction were investigated by the First-principles. The Dirac cone in this heterojunction opens about 11 meV. The contact type of graphene/MoS2 heterojunction could be changed from Schottky to Ohmic contact under the external electric field. The external electric field could also effect the band alignment and orbital coupling in this heterojunction. In addition, we investigate water splitting of electrocatalysis in this heterojunction. We find that the surface of MoS2 has better performance in the hydrogen evolution reaction. The surface of graphene in this heterojunction has lower over potential in the oxidation evolution reaction. Moreover, the optical properties are also improved in this heterojunction. This paper could provide a theoretical basis for the application of graphene/MoS2 heterojunction in the field of nanodevices and electrocatalysis.