One-dimensional hierarchical Cu2O@SnS2 heterojunction with enhanced visible-light-driven photocatalytic activities

Cu2O@SnS2 heterojunction photocatalysts with one-dimensional hierarchical nanostructure were prepared by the solvothermal method. The Cu2O@SnS2 hierarchical nanostructure is composed of Cu2O nanowire core as well as in situ grown ultra-thin SnS2 nanosheets on Cu2O nanowires. The hierarchical Cu2O@SnS2 composite shows higher catalytic activity, and the degradation ratio of MB reaches nearly 100% at 80 min. The first-order reaction kinetic constant of Cu2O@SnS2 is 0.045 min(- 1), which is much higher than that of Cu2O (0.003 min(- 1)) and SnS2 (0.014 min(- 1)). The improvement in photocatalytic performance is mainly due to the formation of typical heterojunction between Cu2O and SnS2. Photo-induced electrons in the CB of Cu2O react with oxygen to form superoxide radicals (center dot O2-) with strong oxidation ability. At the same time, the photo-induced holes in the VB of SnS2 also have strong oxidation ability, and the two can synergistically induce the degradation of pollutants. In addition, SnS2 nanosheets not only provide a large number of reaction sites for photocatalytic degradation, but also facilitate the migration of photo-induced carrier to the surface. The unique hierarchical Cu2O@SnS2 microstructure can also promote multiple light scattering within the material to enhance light absorption. Thus, the one-dimensional hierarchical Cu2O@SnS2 is a promising new visible light catalyst, which has potential application prospect in environmental protection and wastewater treatment.