Structural, optical, photoluminescence and photocatalytic characteristics of sol-gel derived CeO2-TiO2 films

摘要

CeO2-TiO2 films with different Ce/Ti mole ratios have been obtained using a simple sol-gel process. The films (1:0.25 and 1:0.5) containing more than 50% CeO2 content show nanocrystalline characteristics. X-ray photoelectron spectroscopic study shows the variation of Ce4+/Ce3+ ratio with increasing TiO2 content. Films with greater CeO2 content exhibit higher porosity. The observed photoluminescence in the films is attributed to various defects resulting from crystallization and also to the relative amount of Ce3+ in the mixed oxide matrix. The transparency in the films appears to be inversely related to their photoluminescence activity, since the 1:0.5 film, which exhibits the best photoluminescence response, is incidentally also the least transparent film. The presence of photocatalytic activity in these films shows their potential use as an efficient photocatalyst.