| The titanic alkoxide precursor used in the conventional sol-gel method for TiO2 thin films preparation was expensive, and moreover, the substrates would be constrained by the heat treatment process. In order to overcome those shortcomings, TiO2 nanocrystalline sols were synthesized by colloidal chemical method using cheaper raw material (TiCl4), then TiO2 thin films coated on glass were prepared from TiO2 sols via the dip-coating method.The results showed that the TiO2 sols synthesized by colloidal chemical method were anatase with high crystallinity. The TiO2 crystals were needle like and average crystallite size was about 7nm. Optimized preparing conditions of TiO2 sols are follows:pH is 6-7, peptizing temperature is 100℃and peptizing time is 5h, adding amount of H2O2 is H+:Ti4+=10.The surface of PTA flims was smooth and diameter of particles was 86 nm in average. Moreover, coating layers had little influence on roughness and grain diameter. The Three layers films had good adhesion to the substrate and possessed super hydrophilicity and anti-fog function. The photocatalytic activity of the films towards methylene blue reached 90% and the effect was apparent.The tests of self-cleaning and antibacterium showed that the PTA films prepared by colloidal chemical method possessed good self-cleaning and antibacterial properties; the bacterial (Escherichia coli) removal efficiency reached 96%.Studies showed that the TiO2 flims prepared by colloidal chemical method had similar grain morphology and surface structure with the commercial TPX films.The PTA films possessed excellent photocatalytic activity, as well as self-cleaning, anti-fog and antibacterial properties.All of which showed the TiO2 flims prepared by this method had broad application prospect. |
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