PREPARATION OF THERMALLY STABLE MESOSTRUCTUREDTTANA THN FLM AND INVESTIGATION OF TS PHOTOCATALYTIC ACTIVITY FOR DEGRADATION OF SALCYLC

A highly crystalline transparent mesoporous titania film was fabricated by dip coating procedure.The film was fabricated by supramolecular templating technique using a nonionic block copolymer(Pluronic P-123) as structure-directing agent at a low water content alcoholic media. In this reactionconditions, Pluronic P-123 could not form an organized liquid crystal phase so that, the small angleXRD the as-prepared titania film showed a quasi hexagonal mesostructure, but a further increase inthe meso-scale order was surprisingly observed after calcination. The average of pore size andspecific surface area of the precipitation collected from scraping of the TiO2 film calculated to be 6.09 mm and 124.3 mg-, respectively. The film was 2.5 pm thick and had a closely packed ofanatase particles. According to TEM image the particle size of calcinated film is 6-9 mm. Theestimated band gap value of TiO, thin film in the present work is 3.69 ev that is larger than the valuereported in literature for anatase thin film. These results are due to quantum size effects arising fromthe small size of TiO, nanocrystallite in the prepared thin film. The photocatalytic activity of theprepared titania film was evaluated by salcylic acid degradation. The film had excellent Nuclear Science and Technology Research Institute AEOI, end of Kargar street, Tehran, Iran. 2 Simin Janitabar Darziphotocatalytic efficiencies towards salcylic acid. This is attributed to high separation efficiency ofthe photogenerated carriers due to high porosity, large surface area and quantum size effect.

کلیدواژه ها:

mesoporous ، sol-gel preparation ، thermal stability ، photocatalyst ، salcylic acid