Synthesis of SnS2/SnS Heterojunction and Their Enhanced Photocatalytic Properties Under Visible Light

Novel SnS2/SnS heterogeneous composites have been prepared successfully through a one-pot chemical approach by annealing SnO2 nanoparticles in H2S gas at 300 C for different time. The structure and composition of as-prepared SnS2/SnS composites have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectrophotometer (UV-Vis), respectively. Interestingly, the obtained SnS2/SnS composites hold a layered heterojunction structure with high absorption in the visible light range, which show significantly enhanced photocatalytic properties in the degradation of Rhodamine B (RhB) in water under visible light ( > 420 nm) irradiation. In addition, the new composite demonstrates excellent recycling stability as well with 78.5% of RhB degradation even after five reuse cycles. The greatly enhanced photocatalytic performance of the SnS2/SnS composites is mainly attributed to the unique heterogeneous structure which results in proper band gap and efficient charge separation and transfer at the tight bonding interface between SnS2 and SnS.