A unique nanoporous graphene-ZnxCd1−xS hybrid nanocomposite for enhanced photocatalytic degradation of water pollutants

In this work, a novel in-situ solvothermal reduction route has been made to immobilize nanoporous ZnxCd1−xS aggregates on graphene nanoribbons by using PVP as a stabilizer and thiourea as a sulphur source. The nanoporous ZnxCd1−xS aggregates with diameters of 20-30 nm assembled from ZnxCd1−xS nanocrystals (3-5 nm) are homogeneously anchored on graphene nanoribbons and the unique structure of graphene-ZnxCd1−xS nanocomposites has contributed to large specific surface area (102.1 m2g-1). Despite the analogous size and configuration, the nanoporous graphene-ZnxCd1−xS hybrid nanocomposites exhibited composition-dependent photocatalytic performances for the degradation of methyl orange (MO) under visible light. In particular, graphene-Zn0.5Cd0.5S was capable of nearly completely degrading MO in 150 min. The excellent photocatalytic activity was proposed to arise from the synergy effect between nanoporous ZnxCd1−xS aggregates and graphene, the suitable band gap, intimate interfacial contact, and unique nanoporous structure. Moreover, the work provides a simple strategy to prepare various nanoporous graphene-semiconductor nanocomposites.