Study On Preparation And Photocatalytic Properties Of Bi₂s₃ Andits Composite Materials

In rencent years,there are two major worldwide problems energy shortage and environmental pollution.Photocatalytic technology is promising for solving these problems,and more effective than other technologies.The photocatalytic technology process is moderate and is nontoxic.In the process,pollutions can be easily oxidized into small molecular intermediates under the irradiation of visible light or ultraviolet light,ultimately produce may be carbon dioxide,water and other harmless inorganic ions.Bi₂S₃ as a narrow band gap semiconductor materials?1.2?1.7 eV?,Bi₂S₃ is very suitable used as photocatalyst,because it has good visible light absorption.However,due to the narrow band gap,the light generation carrier is easy to compound,and the stability is poor,which restricts its application in the field of photocatalysis.To solve these problems,this paper improves its photocatalytic performance by means of morphological regulation and modification of other semiconductor composites.The specific research contents are as follows:1.In this paper,with the raw materials Bi?NO3?3·5H2O,NaWO4·2H2O and CH3CSNH2,hierarchical Bi₂S₃ hollow microsphere was successfully synthesized via a in-situ topology transformation method from Bi₂WO₆ nanoflowers to Bi₂S₃ product.The Bi₂WO₆ nanoflowers is assembled by nanosheets,and the Bi₂S₃ hollow microsphere with hierarchical structure is assembled by the nanorods.The structure,morphology and optical properties of the as-prepared samples were analyzed by XRD,FESEM,EDS,TEM,DRS and PL,respectively.The photocatalytic of the samples was evaluated by degradation of organic dye RhB and CIP.The degradation rate of Bi₂WO₆ to RhB and CIP was 45%and 22%respectively in visible light.The degradation rate of RhB and CIP at the same time of Bi₂S₃ was 96%and 75%respectively,indicating that the hollow spherical Bi₂S₃ had better photocatalytic performance.2.Bi₂S₃/Bi₂WO₆ microspheres were synthesized by hydrothermal method,The structure,chemical composition of Bi₂S₃/Bi₂WO₆ was studied by XRD and XPS.The morphologies of samples were characterized by FESEM,TEM and the optical absorption was detected by UV-vis DRS.The suppression of the electron-hole pair recombination was studied by PL analysis.The photocatalytic of the samples was evaluated by degradation of organic dye RhB and CIP.According to the experimental result,the hollow microspheres of Bi₂S₃/Bi₂WO₆ have excellent absorption in the visible light.The visible-light-driven activity was enhanced by the heterojunction Bi₂S₃/Bi₂WO₆.The degradation rate of RhB and CIP reached 79.2%and 62.85%respectively.3.A Z-scheme AgInS₂/Bi₂S₃ heterojunction photocatalytic material was synthesized by a hydrothermal method.The structure,morphology,chemical composition and state of the as-prepared samples were analyzed,respectively.The photocatalytic of the samples was evaluated by degradation of organic dye RhB and CIP.The results show that AgInS₂/Bi₂S₃ microspheres excellent absorption in the visible ligh Under visible light irradiation,the degradation rate of RhB and CIP reached 96%and 84.7%,respectively.The photocatalytic mechanism of Z-scheme AgInS₂/Bi₂S₃ heterojunction was discussed.