The Study Of Preparation And Photocatalytic Degradation Of Rhodamine B Of Bi-based Photocatalysts

Recently,photocatalytic technology has attracted extensive attention because of its applications in energy and environmental pollutants treatment.Bismuth-based catalysts which can response to visible light have been widely studied due to their excellent photocatalytic properties.However,Unfavorable factors such as recombination of photo-generated carriers,low utilization of solar energy limit the catalytic activity of Bismuth-based catalysts.Therefore,study of preparation and photocatalytic properties of high effective and stable Bi-based photocatalysts would be illustrated in this thesis.The main contents are as follows:1.The ?-Bi₂O₃/TiO₂ nanoparticles were synthesized through a two-step hydrothermal method.Transmission electron microscopy?TEM?,X-ray photoelectron spectroscopy?XPS?,X-ray diffraction?XRD?and UV-vis diffuse reflection spectroscopy?DRS?were employed to clarify the structure and morphology of the ?-Bi₂O₃/TiO₂ photocatalysts.The photocatalytic activity of the composite was evaluated by using Rhodamine B?RhB?as model contaminant.Compared with the single phase ?-Bi₂O₃ or TiO₂,the ?-Bi₂O₃/TiO₂ exhibited better photocatalytic activity.The catalyst prepared with molar ratio 1:5 of ?-Bi₂O₃ and TiO₂ showed the best photocatalytic activity.98.5% RhB was degraded within 150 min under visible light irradiation.After three terms of recycling,the catalyst still exhibited good photocatalytic activity.2.?-Bi₂O₃/Bi₂WO₆ nanoparticles were prepared by hydrothermal method,the samples were characterized by TEM,UV-Vis,XPS,XRD and DRS.The photocatalytic activities of ?-Bi₂O₃/Bi₂WO₆ for degradating RhB were investigated under visible light irradiation.The results indicated that the degradation rate reached 95% after 60 min irradiation with addition amount of 0.15g/80 mL and optimal doping amount?mass ratio?of ?-Bi₂O₃ 10%.The ?-Bi₂O₃/Bi₂WO₆ composites is highly stable even after three times recycling utilization which will have great practicial applications.3.As a precursor,BiOBr nanoparticles catalyst were prepared with a simple liquid phase method,Bi2S3/BiOBr photocatalyst was synthesized through a facile and economical ion exchange method between BiOBr and thioacetamide?TAA?.TEM,XRD,XPS and DRS were employed to characterize Bi₂S₃/BiOBr structures.photocatalytic activity of Bi₂S₃/BiOBr was evaluated by degradation of RhB,98% RhB could be degraded within 24 min under visible light irradiation,which was much higher than that of pure Bi₂S₃?BiOBr.It is found that Bi₂S₃/BiOBr nanocomposites have good stability through its recycling utilization.4.Co²⁺/Bi₂WO₆ nanoparticles were prepared by hydrothermal method,and characterized through XRD,TEM,DRS and XPS.The effects of the doping amount of Co²⁺,the amount of Co²⁺/Bi₂WO₆ catalyst and different scavengers on their photocatalystic activity were discussed.The results showed that the degradation rate reached to 97.8% after 75 min reaction when the doping molar ratio was n(Co²⁺): n?Bi₂WO₆?=3%,the catalyst dosage was 0.05g/80 mL.It showed better photocatalystic properties than that of undoped Bi₂WO₆ nanoparticles.