PHOTOCATALYTIC ACTIVITY OF MACROPOROUS SOL-GEL TIO2-THICK FILM INCORPORATING P-25 TIO2

Macroporous thick films of TiO2 using a single step coating by sol-gel spin-coating procedure and low annealing temperatures at 400°C were deposited on glass substrates. The method relies on oxide nanopowder filler in an optimized precursor solution. The films of approximately 4 µm thick are well adherent to the substrate, show homogeneously distributed open porosity, and are superhydrophilic. The TiO2 films were characterized by X-ray diffractometer, scanning electron microscope and ultraviolet–visible spectrophotometer. Photocatalytic activity of these films was evaluated by light induced degradation of 25 mL aqueous solution of methyl orange with initial concentration of 2 mM and a pH of 5.6 using a high pressure mercury lamp show a remarkable photocatalytic activity with a rate constant value of 4.4 X 10-3 min-1