Study On The Preparation Of SnS₂-based Nanomaterials And Their Photocatalytic Performance

As a typical two-dimensional layered semiconductor material,tin disulfide(SnS2)has attracted a great deal of attention because of its excellent optical,electrical,magnetic and chemical catalytic properties.So far,the material has already been widely used in many fields,such as lithium ion battery,photocatalysis,solar cell,gas sensor/biosensor,and so on.It is considered to be one of the most promising semiconductor materials.In recent years,with the rapid development of printing and dyeing industry,dye wastewater has gradually become one of the most important pollution sources in the present water environment system.It has become an important research direction in the field of water treatment to seek an effective way to deal with the dye wastewater.At the same time,due to the increasingly serious energy crisis and air pollution caused by the improper use of traditional fossil fuels,it is necessary for us to develop new energy vigorously.Semiconductor photocatalytic technology can take the inexhaustible solar energy for degradation of organic pollutants and hydrogen production from water splitting.It provides a great possibility to solve these two problems and gets people's attention increasingly.Obviously,the development of high efficiency and low cost semiconductor photocatalytic materials is the key to promote the industrialization of this new technology.Here,G-Bi2S3/SnS2 heterostructures have been successfully established by a simple in-situ growth method,using SnS2 nanosheets,Bi3+ and S2-as precursors.The composition,morphology and optical properties of the prepared composites were characterized by X-ray diffraction,transmission electron microscopy,scanning electron microscopy,inductively coupled plasma spectroscopy,X-ray photoelectron spectroscopy,UV-Vis diffusion reflectance spectroscopy and room temperature photoluminescence spectra.Meanwhile,their photocatalytic performances were evaluated by degrading methyl orange(MO)in aqueous solution(50 mg/L)under visible light(? > 420 nm)irradiation.The study showed that the coupling of Bi2S3 could greatly enhance the photocatalytic activity of SnS2,and the new catalysts were easier to be recycled without a decrease in the photocatalytic activity.Effective separation of photoinduced electron-hole pairs may be the main reason for the improvement of the activity of G-Bi2S3/SnS2 nanocomposites.In addition,the E-Bi2S3/SnS2 composites were prepared by ion exchange methodbased on the premise that SnS2 nanosheets and Bi3+ were used as precursors.Also,their composition,morphology and photocatalytic properties were characterized and measured.The enhanced photocatalytic activity proved that the ion exchange method can also be used to build highly efficient heterostructures between SnS2 and Bi2S3.According to the reports,ion doping is also an effective way to improve the photocatalytic activity of semiconductor.In this study,Ce3+ was used to modify SnS2.The Ce-SnS2 with few-layered structure was synthesized by hydrothermal method,and its catalytic activity was evaluated by photocatalytic water-splitting reaction.The results showed that the doping of Ce3+ did play an important role in improving the photocatalytic performance of SnS2.