Preparation, Characterization And Application Of Anatase Nanosized Titanium Dioxide Sol

Recently, titanium dioxide (TiO₂) with photocatalytic activity has been research hotspot and many efforts have been made to develop its applications. At present, TiO₂ -based products, such as TiO₂ powder and TiO₂ film, are usually obtained from calcining at high temperature, and it is not widly used in the industry. So it is significant to prepare TiO₂ powder or film at lower temperature without calcination. This paper has focused on the preparation of nanosized TiO₂ with high photocatalytic activity at low temperature and its applications.Firstly, TiO₂ sol was prepared using titanium tetrachloride as precursor below 100 ℃. XRD and TEM were used to examine the microstructure of the TiO₂ sol. The results indicated that the produced sol contained anatase TiO₂ particle with a size smaller than 10 nanometers. The photocatalytic activity of the sol in the sunshine was tested by the degradation degree of dyes. The results showed that a degradation rate of 91.5% was reached implying the sol had high photocatalytic activity. The stability of the TiO₂ sol was tested in environments with different pH values, and the results showed that it was very stable.Secondly, various TiO₂ sols were prepared under different conditions. The effects of preparation conditions on the microstructure and performance of TiO₂ sol were studied by XRD, TEM, UV-vis and photocatalytic analyses. Orthogonal experiments were carried out to optimize the preparation conditions of TiO₂ sol. It was shown by the photocatalytic analyses of the TiO₂ sol prepared under the optimized conditions that the degradation rate of dyes reached 99.1% and the sol exhibited good antibacterial ability on bread. The reactions involving in the formation of TiO₂ sol were also discussed.Thirdly, TiO₂ film was deposited on to glass-spring by cycles of dip-coating method. The photocatalytic performance of TiO₂ film was demonstrated through photocatalytic analyses. The results showed a 4-layer TiO₂ film had high photocatalytic activity and high adherence to the substrate. On a certain scale, the higher the drying temperature was, the weaker the photocatalytic activity of TiO₂ film...