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Hydrothermal Synthesis And Photocatalytic Performance Of Spherical MoS2/TiO2

Posted on:2020-02-06Degree:MasterType:Thesis
Country:ChinaCandidate:J Y SuFull Text:PDF
GTID:2428330590482221Subject:Integrated circuit engineering
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Environmental issue and energy crisis are two major problems closely related to human survival and development.Using semiconductor technology to solve the problem of organic pollution is one of the central issue in the field of semiconductor materials in recent years.The spherical MoS2/TiO2 heterostructure composites are prepared by hydrothermal method,and their photocatalytic properties under visible light have been studied,which are used to improve their light energy utilization and quantum yield.Using glucose as raw material,the reaction temperature and reaction time are selected as variables,and carbon microspheres are prepared by hydrothermal method based on carbon microsphere size,morphology and monodispersity.The reaction products are characterized by X-Ray Diffraction?XRD?and Scanning Electron Microscope?SEM?.The optimum preparation parameters are as follows:the reaction temperature is 200°C,the reaction time is 10 h.The carbon microspheres prepared are used to interact with metal ions in butyl titanate as templates,which is due to characteristics of its surface functional groups can easily interact with metal ions,and the chemical reaction rate is controlled by controlling the hydrolysis rate of butyl titanate to control the morphology of the substrate material.At the end of the reaction,the products are subjected to high temperature annealing to obtain hollow spherical TiO2.The hollow spherical TiO2 is used as the base material.The spherical MoS2/TiO2 composites were prepared by hydrothermal method.In the composite preparation process,the performance parameters of the heterostructure semiconductor photocatalytic material are optimized by orthogonal experiment and single factor experiment,and the related characterization test methods such as XRD,SEM,Transmission Electron Microscope?TEM?,etc.are applied to analyze the material to determine its crystal structure,microscopic morphology and atomic vibration mode.The optimum composite material preparation process parameters are:Mo:S atomic ratio is1:3.5,Mo:Ti atomic ratio is 3:1,reaction time is 24 h,reaction temperature is 200°C,and precursor liquid pH is 3.The photocatalytic effects of spherical MoS2/TiO2 composites on several organic dyes were studied under visible light conditions.The results show that the spherical MoS2/TiO2composites exhibit good photocatalytic effect on rhodamine B and methylene blue.After photocatalysis for 120 min,the degradation rates are above 90%.The photocatalytic effect of that on methyl orange is low,and the degradation rate is about 78%.The catalytic effect of that on Congo red is very weak,and the degradation rate is about 35%.At the same time,the composite materials have good light stability and reusability,and can be used as a stable and recyclable photocatalytic material with good commercial application prospects.The photocatalytic mechanism of MoS2/TiO2 is further explored and analyzed in combination with literature and experiments.Based on the optimization process,the effects of different types of surfactants on the photocatalytic properties of the composites are further explored.The results show that the addition of a certain amount of anionic surfactant?SDBS?for composites can significantly improve the photocatalytic performance of the composites under visible light,while the addition of nonionic surfactant?PVP?for composites can greatly improve the adsorption capacity,and the fading of the dye can be achieved at the end of the dark reaction.Based on the experimental results,the photocatalytic mechanism of MoS2/TiO2 was analyzed.
Keywords/Search Tags:hydrothermal method, MoS2/TiO2, nanocomposites, photocatalysis, surfactants
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