One-dimensional hierarchical Cu 2 O@SnS 2 heterojunction with enhanced visible-light-driven photocatalytic activities

Cu 2 O@SnS 2 heterojunction photocatalysts with one-dimensional hierarchical nanostructure were prepared by the solvothermal method. The Cu 2 O@SnS 2 hierarchical nanostructure is composed of Cu 2 O nanowire core as well as in situ grown ultra-thin SnS 2 nanosheets on Cu 2 O nanowires. The hierarchical Cu 2 O@SnS 2 composite shows higher catalytic activity, and the degradation ratio of MB reaches nearly 100% at 80 min. The first-order reaction kinetic constant of Cu 2 O@SnS 2 is 0.045 min − 1 , which is much higher than that of Cu 2 O (0.003 min − 1 ) and SnS 2 (0.014 min − 1 ). The improvement in photocatalytic performance is mainly due to the formation of typical heterojunction between Cu 2 O and SnS 2 . Photo-induced electrons in the CB of Cu 2 O react with oxygen to form superoxide radicals (·O 2− ) with strong oxidation ability. At the same time, the photo-induced holes in the VB of SnS 2 also have strong oxidation ability, and the two can synergistically induce the degradation of pollutants. In addition, SnS 2 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 Cu 2 O@SnS 2 microstructure can also promote multiple light scattering within the material to enhance light absorption. Thus, the one-dimensional hierarchical Cu 2 O@SnS 2 is a promising new visible light catalyst, which has potential application prospect in environmental protection and wastewater treatment.