Preparation Of TiO₂ Film And Its Application For Photocatalytic Degradation Of Methyl Orange

The way of using TiO₂ photo-catalyst to erase the organics is an admirable way among many pollution treating approaches, which is capable of minerizing completely almost all the oranic compounds into CO₂ and H₂O, etc. However, there is great difficulty in separating and reusing the very fine TiO₂ powder, thus immobilizing TiO₂ powder to some suitable supports successfully is the only wayout in real application; And the photo-catalytic TiO₂ films have promising application in the environmental protection, such as air purification, waste water treatment, bacillus resistance, pollution elimination, mist prevention and self-cleaning.Firstly, slide glass, Ti(OC₄H₉)₄ and C₂H₅OH were chosen to serve as the substrate, Ti-precusor and solvent respectively; At the same time, sol-gel method and dip-coating technique were adopted to prepare the photo-catalytic TiO₂ films with or without SiO₂ sub-layers. Results showed that it's necessary to calcine the TiO₂ films at 500℃ for 1.5 h to get its best photo-catalytic activity; and 1 0.1mol/L nitric acid post-treatment or pre-coating SiO₂ sub-layers would improve the activity, owing to the removal of Na⁺ ions in the TiO₂ films or just keeping the Na⁺ ions in the SiO₂ sub-layers.Secondly, the SiO₂-TiO₂ complex films were prepared, and complex films doped with rare earth La or Ce were also prepared via an non-uniform way. Results showed that the introduction of SiO₂ was helpful to the photo-catalytic activity of TiO₂ films; Likewise, La or Ce was favorable to the photo-catalytic activity of TiO₂ complex films, and Ce was superior to La, and their best doping...