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 di ffraction (XRD) and Raman spectra analyses. The photocatalytic propert ies of the sol-gel derived films were assessed by measuring the photod egradative oxidation of Rhodamine B in aqueous solution and compared w ith Degussa P-25 coated films. These SG-TiO2 films showed much higher photoactivity than P-25 coated films at the initial time of the reacti on. Results of this study also indicate that the photodegradative mech anisms assisted by the two kinds of films are obviously different: hig hly 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.