Construction of SnS₂–SnO₂ heterojunctions decorated on graphene nanosheets with enhanced visible-light photocatalytic performance

Heterostructures formed by the growth of one kind of nanomaterial in/on another have attracted increasing attention due to their microstructural characteristics and potential applications. In this work, SnS₂–SnO₂ heterostructures were successfully prepared by a facile hydro­thermal method. Due to the enhanced visible-light absorption and efficient separation of photo-generated holes and electrons, the SnS₂–SnO₂ heterostructures display excellent photocatalytic performance for the degradation of rhodamine (RhB) under visible-light irradiation. Additionally, it is found that the introduction of graphene into the heterostructures further improved photocatalytic activity and stability. In particular, the optimized SnS₂–SnO₂/graphene photocatalyst can degrade 97.1% of RhB within 60 min, which is about 1.38 times greater than that of SnS₂–SnO₂ heterostructures. This enhanced photocatalytic activity could be attributed to the high surface area and the excellent electron accepting and transporting properties of graphene, which served as an acceptor of the generated electrons to suppress charge recombination. These results provide a new insight for the design and development of hybrid photocatalysts.