| Photocatalytic oxidation process that is used for the removal of volatile organic compounds (VOCs) has become a focus of air pollution treatment, and the preparation of TiO2 with high photoactivity is the key for its industrialization. This dissertation focused on the two major limiting factors which impede the enhancement of photocatalytic activity: the recombination between the photogenerated electrons and holes and the low efficiency for the utilization of visible light. Metal ion doping was used to inhibite the charge-carrier recombination and enlarges the responding area to light which results in enhanced photodegradation. Metal-doped nano-TiO2 with high photoactivity was prepared and characterized by means of XRD, TG-DSC, TEM-EDS and UV-VIS, and then the doping mechanism was explored based on the characterization results. The photoactivity of the elaborated powders was studied following the degradation of gaseous toluene of the indoor air.Pure nano-TiO2 particle was prepared through sol-gel method. Its photoactivity and effects including the wavelength of the lamp, temperature, catalyst loading, and the initial concentrations that influence the photodegradation of gaseous toluene were discussed in a batch reactor. The results showed that the photoactivity of the metal-doped TiO2 was 1.5 times than that of P25. The toluene destruction efficiency when TiO2 was irradiated by 254 nm UV light was 40 times higher than that 365 nm UV light was used. The reaction rate for the photocatalytic oxidation of toluene apparently increased, reached a maximum and then decreased with higher catalyst loading, and optimum catalyst loading was found to be 1.51mg·cm-2. Temperature had little effect on the reaction rate at the room temperature. Reaction rate was increased as the initial concentration of toluene was higher.The rate equation was fitted by the Langmuir-Hinshelwood kinetic model which, at low toluene concentration, approaches the first order model, and the kinetic...
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