Preparation of TiO2 nanofilm via sol–gel process and its photocatalytic activity for degradation of methyl orange

The preparation of TiO2 nanofilm was conducted on common glass via the sol–gel process. Glacial acetic acid and diethanolamine were used as inhibitors to prepare acidic and alkaline TiO2 sol, respectively. XRD, SEM, and EDS characterization showed that the film prepared from acidic TiO2 sol had a narrow particle size distribution of ∼15–30 nm and relatively poor particle crystallization while in the case of the film from alkaline TiO2 sol the nanoparticles were in a wide range of ∼10–80 nm and well crystallized. The photolysis evaluation through MO degradation revealed that the film from acidic sol possessed apparently better photocatalytic activity than that from alkaline sol. Heat treatment with longer time led to a ∼50% increase of the photocatalytic activity for the film.