Efficient Photocatalyst Titanium Dioxide Nanoparticles Preparation And Applied Research

In the thesis, four methods for the preparation of nanosized TiO2 were investigated, and particles TiO2 samples were characterized using SEM, FT-IR, XRD, UV-Vis and Laser Particle Size Analyzer. TiO2 colloids prepared by TiCl4 hydrolyzing under control were stable, the obtained particles were globular in shape and its grain size was in the range of 10-30nm. The photocatalysis activity of TiO2 colloids was evaluated by meaning the concentration of methyl orange under UV illumination.With Piezoelectric Quartz Crystal Microbalance (QCM), the adsorption of organic gases and metallic ions on the surface of TiO2. Due to highly hydrophilic behavior of TiO2, a large amount of adsorption for polarity organic gases was observed and little adsorption for weak polarity organic gases. After modification of T1O2 with silica oil, the surface of TiO2 also had stronger adsorption for weak polarity organic gases. In liquid phase, the surface of TiO2 possessed selective adsorption for metallic ions, Ag+ and Fe3+ ions have larger amount of adsorption on the surface of TiO2 (7.96mmolFe3+/gTiO2).The nanosized TiO2-pesticide complex was prepared by two methods (i.e., direct mixture of powders and in-situ direct preparation). Its photodegradation and biological toxicity were studied. Experimental results showed that the nanosized TiO2-pesticide complex was obvious photodegradation, its residual time in the body of plant was significantly reduced and its biological toxicity increased to ,1.68 times comparing with traditional pesticides.