Preparation And Photoactivity Of TiO₂ Nanocomposites

In recent years, TiO₂ nanoparticles have attracted much attention of the scientists, due to their excellent semiconductor characteristics and photocatalytic activity. The research results show that TiO₂ nanoparticles can decompose the organic pollutants, such as hydrocarbon halogenate, phenol, acetone, and formaldehyde, into carbon dioxide and water. Therefore, TiO₂ nanoparticles are much significance in the purification of water, the elimination of air pollution. Also, they can be used as the photoanode for the fabrication of solar cells.Whereas, pure TiO₂ nanoparticles have some shortages in application, since pure TiO₂ can only absorb UV light due to its wide band gap. Therefore, the photodegration efficient of pure TiO₂ is low. Novel TiO₂ nanocomposits can make TiO₂ more sensitive to the visible light and be effectively used to the elimination of environmental pollutants and solar cells.In this paper, some TiO₂ nanocomposites were prepared with titanium butoxide (TBOT) materials by sol-gel method. The products as-obtained were characterized by a series of equipments, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDXA), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), ultraviolet (UV) analysis, photoluminescence (PL) analysis, Laser Raman (LR) analysis, differential scanning calorimetric (DSC) analysis and thermogravimetric (TG) analysis. In addition, the formation mechanism of the TiO₂ nanocomposites was discussed.Our main work as follows:1. The preparation and characterization of TiO₂ nanoparticlesThe anatase TiO₂ nanoparticles were prepared by a novel sol-gel approach. The products were characterized by TEM, XRD, TG, IR. The effect factors, such as the acid, alcohol, surfactants, were studied.2. The preparation of SeO₂/TiO₂ nanocomposite and its photocatalytic activitySeO₂/TiO₂ nanocomposite was obtained by calculation and water bathing methods respectively. The products were characterized by SEM, XRD, HRTEM, UV, XPS, TG, IR. A series of characterizations showed that two oxides in the nanocomposite were not physically mixed, and the Ti in the TiO₂ cell lattice may be replaced by Se. The results show that the SeO₂/TiO₂ nanocomposite has higher photocatalytic activity than pure TiO₂ nanoparticles. The mechanism of this reaction was discussed.3. The preparation of TeO₂ and TeO₂/TiO₂ nanocompositeTiO₂ nanoparticles and TeO₂/TiO₂ nanocomposite with the size of 20nm have been prepared by sol-gel process and liquid deposition method, respectively. The products were characterized by SEM, TEM, XRD, UV-Vis, IR, LR, EDXA, etc. The effect factors and the formation mechanism of the products were discussed.4. The preparation of V₂O₅/TiO₂ nanocompositeV₂O₅/TiO₂ nanocomposite was prepared with TBOT by the sol-gel method. The product as-obtained was characterized by SEM, TEM, XRD, EDXA, ect. The effect factors and the formation mechanism of the products were discussed.