Effect of cerium oxide doping on the photocatalytic properties of rutile TiO<inf>2</inf> films prepared by spray pyrolysis

Abstract

The spray pyrolysis is fast and simple method for deposition of CeO2 – rutile TiO2 coatings on stainless steel substrate. The coatings were deposited on stainless steel substrate and characterized by XRD, AFM, XPS, Raman, DRS and photoactivity test for methyl orange decolorization. Photoactivity of CeO2 – rutile TiO2 coatings increase with increasing CeO2 content up to 5 wt% and further increase of CeO2 content leads to decrease of photoactivity. Improvements of photoactivity originate from close contact between CeO2 and rutile TiO2 particles which create numerous centers able to produce very reactive radical species. Besides, the close contact between the CeO2 and rutile TiO2 provides easier charge transfer facilitating the formation of electron/hole pairs that is a necessary step in the overall photocatalytic process.