| To handle toxic organic matter by using of TiO2nanoparticles as photocatalyst is a low-carbon green protectionthe at the beginning of the21st century. However, the band gaps of pure TiO2is so wide (3.2eV) that its catalytic activity can display only in the ultraviolet excitation, other wavelengths of sunlight cannot be absorbed by it, caused the pure TiO2in the limitation of its wide applications. Therefore, the modification of TiO2via sensitization is a very simple and effective method to solve the above problem.In this thesis, eosin and chlorophyll were used as the photosensitizers to modify the TiO2nanoparticles. TiO2nanoparticles sensitized with sensitizers were prepared via sol-gel method. Samples characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy(FT-IR), ultraviolet-visible spectrum (UV-vis) and so on. The effects of sensitization TiO2Nanoparticles on the cystal phase, crystallite sizes, suface topography and optical property of the catalysts were investigated. The photocatalytic activities of the sensitized TiO2were investigated through methyl orange degradation under visible light irradiation, where the fluorescent lamp was used as light source. The results exhibit that sensitization can maintain the anatase of TiO2, also little influence on its morphology; Sensitized TiO2Nanoparticles poss-esses strong absorption in visible region, for the co-operation effect of elements co-sensitized with two kinds of photosensitizers, cause the spectral response to direction of visible light, the spectral response range TiO2has been expanded. The results show that:The performance of TiO2nanoparticles for photocatalytic degradation rate (PDR) of methyl orange has been improved obviously for droping and sensitizing. The PDR of methyl orange reached61.33%under the conditions of eosin concentration of30mg/L, chlorophyll concentration of20mg/L, sensitization time of8h and sensitization temperature of30-℃. |
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