Flower-shaped BiOI@SnS2 Z-scheme heterojunction for enhancing visible-light-driven photocatalytic performances

Flower-shaped BiOI@SnS2 nanocomposites were synthesized by the coprecipitation method. The effects of different composite ratios on the chemical composition, microstructure, morphology, optical properties, photoelectric chemical properties and photocatalytic properties of the samples were discussed. And the photocatalytic performance of the samples were evaluated by the photodegradation of Rhodamine B (RhB) in an aqueous solution under the xenon lamp. The experimental results demonstrated that BiOI@SnS2 nanocomposites were three-dimensional nanoflower-like microsphere structures with good crystallization. BiOI@SnS2 nanocomposites can improve visible light absorption due to their larger specific surface area and optimized energy band structure. BiOI@SnS2 heterojunction can effectively broaden the light visible light response range, accelerate the separation of photogenerated carriers and inhibit the recombination of electron-hole pairs. BiOI@SnS2 Z-scheme heterojunction exhibit excellent photocatalytic activity compared with pure BiOI and SnS2 photocatalysts in the degradation of RhB and the photocatalytic degradation rate of BiOI@SnS2-2 reached 76.8% after 90 min. In addition,.O2− and OH as the main active species in the photocatalytic degradation of RhB.