Photodegradation of rhodamine B catalyzed by TiO2 thin films

Transparent TiO2 thin films were prepared on glass substrates by a sol-gel method. They were confirmed to be anatase crystallites by Xray diffraction (XRD) and Raman spectra analyses. The photocatalytic properties of the sol-gel derived films were assessed by measuring the photodegradative oxidation of Rhodamine B in aqueous solution and compared with Degussa P-25 coated films. These SG-TiO2 films showed much higher photoactivity than P-25 coated films at the initial time of the reaction. Results of this study also indicate that the photodegradative mechanisms assisted by the two kinds of films are obviously different: highly efficient and fast N-de-ethylation accompanied the degradation of Rhodamine B catalyzed by a SG-TiO2 thin film, whereas only degradative reaction took place when P-25 coated film existed. (C) 1998 Elsevier Science S.A. All rights reserved.