| The issues of environment and energy have mainly restricted development of social. Photocatalytic oxidation technology was considered to be one of the most promising application technologies in the field of environment and energy because semiconductor photocatalyst can convert solar energy into chemical energy as well as degrade organic compounds. TiO2 were considered the most likely to be put used in actual semiconductor catalyst because of its stable chemistry, safety, non-toxic,relatively cheap and no light corrosion among various semiconductor catalyst.However, TiO2 had a high band gap energy that was only excited by ultraviolet light,had a low light energy utilization ratio, and the photo-generated electrons and holes were easily recombination that lead to low quantum efficiency and resulting in a low photocatalytic efficiency. Therefore, this paper aimed at improving light absorption properties of TiO2 and the quantum efficiency of catalyst by the way of morphology controlling, surface modification, nonmetal doping, semiconductor, and systematically study its photocatalytic activity, discusses the reasons of improvement of catalytic activity as well. Some new and interesting results are as followings:1. High catalyst efficiency TiO2 hollow sphere with-NO2 were prepared based on the biomass carbon microspheres as templates by a single-step sol-gel process. The information of morphology, composition and structure of the catalyst were characterized by fluorescence, UV-Vis diffuse reflectance, X-ray photoelectron spectroscopy, X-ray diffraction, field emission scanning electron microscopy,transmission electron microscopy, surface area and pore characteristics analysis and fourier transform infrared spectroscopy, and characterized the activity of the photocatalyst through degradation of methyl orange, p-chlorophenol and hydrogen production. The results showed that perfect anatase TiO2-NO2 hollow spheres were prepared with a better photocatalytic activity. But TiO2-NO2 bulk phase have higher adsorption capacity and photocatalytic activity to methyl orange compared with TiO2-NO2 hollow spheres.2. TiO2 hollow spheres and H3PW12O40/TiO2 hollow spheres were prepared based on the biomass carbon microspheres as templates. The information of morphology,composition and structure of the catalyst were characterized by PL, UV-Vis diffuse reflectance, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results showed that lots of TiO2 hollow spheres had been prepared used the carbon microspheres as template and the photocatalyticactivity of TiO2 got improved by doping phosphotungstic acid. The consequence shows that the TiO2 hollow spheres dipping with phosphotungstic acid have the highest activity.3. TiO2 hollow spheres whose morphology can be controlled coupling with g-C3N4 were successfully prepared based on Chapter Ⅲ. The morphology, electrical properties and photocatalytic activity of the catalyst were characterized and studied.The results showed that the structure of TiO2 hollow was more stable after coupling with g-C3N4, and the photocatalytic activity of g-C3N4/TiO2 was superior to the g-C3N4/TiO2 bulk phase.4. TiO2 nano-microspheres doping with F were successfully prepared based on perfluorooctane sulfonates（PFOS） as templates. The information of analyzed samples were characterized by scanning electron microscopy, X-ray diffraction patterns UV-vis diffuse reflectance spectroscopy and PL. The results showed that F-TiO2 microspheres have blue-shift to the absorption.The reasons of this blue-shift were discussed logically in this paper. Meanwhile, 4-FP degradation experiment showed that the photocatalytic activity of TiO2 nanometer microspheres was obviously better than that of bulk phase TiO2. |
