Enhanced photocatalytic H2 evolution on ZnS loaded with graphene and MoS2 nanosheets as cocatalysts

Abstract

Graphene and MoS₂ nanosheets modified ZnS nanoparticles were successfully prepared by a simple one-pot hydrothermal route in the presence of graphene and MoS₂ nanosheets. The resultant ZnS/graphene/MoS₂ nanocomposites exhibited significantly enhanced photocatalytic activity and good recurrence stability in H₂ evolution from water splitting. When the loading content of graphene was 0.25 wt% and that of MoS₂ was 2 atom%, the ZnS/graphene/MoS₂ nanocomposite reached a high H₂-evolution rate of 2258 μmol h⁻¹ g⁻¹ under a 300 W Xe lamp irradiation, which is about 2 times that of ZnS alone. The synergistic effect of cocatalysts contribute to the high performance of the hybrid photocatalyst, where graphene serves as an excellent electron acceptor and transporter, and MoS₂ nanosheets provide a source of active reactive sites. It demonstrates that the exfoliated MoS₂ nanosheets, achieved by the liquid exfoliation from natural molybdenite, can be used as an efficient cocatalyst to prepare high-performance photocatalysts in hydrogen evolution from water splitting.