Synthesis,Modifide And Properties Of Molybdate Bismuth Visible-light Photocatalysst

In this thesis, the synthesis and photocatalytic activity for the visible-light photocatalyst bismuth molybdate were investigated. γ-Bi2MoO6nameplates were successfully prepared via ionic liquid assisted. The effect of the ionic liquid [BMIM]Br on the formation of y-Bi2MoO6was discussed in detail. A coupled system of Cu2O/Bi2MoO6was successfully synthesized by solvothermal method. The role of two conductors compound improved the photocatalytic performance was studied. Fluorinated Bi2MoO6photocatalyst was synthesized by a simple hydrothermal process. The photocatalytic performance of the products was compared. Bi2MoxW1-xO6(x=0～1) solid solutions have been successfully synthesized via a facile hydrothermal method. The photocatalytic activities of the products were evaluated under visible light.1. γ-Bi2MoO6nanoplates:Ionic liquid assisted hydrothermal synthesis and enhanced photocatalytic activityy-Bismuth molybdate nameplates were synthesized via an Ionic liquid assisted hydrothermal system. The structure and morphology of the as-synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, FT-IR spectrum and UV-vis diffuse reflectance spectra. The effect of the ionic liquid [BMIM]Br on the formation of y-Bi2MoO6was discussed in detail. The photocatalytic activity of the as-synthesized samples was evaluated by monitoring the degradation of crystal violet solution. The result showed that y-Bi2MoO6nanoplates revealed much higher photocatalyst activity.2. Prepared, characterization and photocatalytic activities of Cu2O/Bi2MoO6A coupled system of Cu2O/Bi2MoO6, with high visible-light photocatalytic activity was successfully synthesized by solvothermal method via ethylene glycol(EG) as;u solvent. The products were characterized by X-ray power diffractometer (XRD), scanming electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Ultraviolet and visible light spectrum (UV-vis) was employed to estimate the band gap energy of as-prepared samples, which exhibited significant absorption in the visible light region. The activity of the samples was evaluated using Crystal violet (CV) as a model organic compound. As a result, the sample of the mole ratio of Mo/Cu is0.08exhibited superior visible-light-driven photocatalytic performance with the degradation ratio of95.60%within100min. The effects of the amount of copper on improving the catalytic performance were investigated and the possible mechanism of the system was proposed.3. Enhanced photocatalytic activity of Bi2Mo O6catalyst via fluorine dopingFluorinated Bi2Mo O6photocatalyst was synthesized by a simple hydrothermal process. The obtained products were characterized by X-ray diffraction, UV-Vis diffuse reflectance spectra and FT-IR spectrum.The effects of fluorine doping on crystal structure and photocatalytic activity of Bi2MoO6photocatalyst were investigated. Moreover, the strength of absorption in the visible light region increased after doping with fluorine. With an increase of fluorine doping concentration, Fluorinated Bi2MoO6presented the enhanced photoactivity for the RhB degradation under the visible light. It exhibited the highest photocatalytic activity when the optimal atomic ratio of F/Mo was0.3. This mainly originated from the increase of transfer rate of photogenerated electrons to the photocatalyst surface.4. Hydrothermal synthesis, characterization and photocatalytic activities of Bi2MoxW1-xO6solid solutionBi2MoxW1-xO6(x=0～1) solid solutions have been successfully synthesized via a facile hydrothermal method. The obtained products were characterized by X-ray diffraction, UV-Vis diffuse reflectance spectra and FT-IR spectrum. From the XRD patterns and FT-IR spectrum of the as-synthesized products, the composition and structure were analyzed. Accoding to the DRS calculations, the band gap of the samples were respectively2.75,2.55,2.50,2.45,2.59and2.63eV when x equaled to0,0.25,0.5,0.75,0.9and1. That revealed the formation of soluble solid solution. The photocatalytic activities of the products were evaluated by monitoring the degradation of RhB under visible light. It was found that Bi2Mo0.75W0.25O6solid solution exhibited the highest photocatalytic activity. This mainly attributed to the special structure of solid solution and the lower energy band gap.