Photocatalytic properties of TiO$_{2}$-Fe$_{2}$O$_{3}$ and ZnO-Fe$_{2}$O$_{3}$ films.

Morphological, optical and photocatalytic properties of TiO$_{2}$-Fe$_{2}$O$_{3}$ and ZnO-Fe$_{2}$O$_{3}$ samples were studied. The layers were deposited on glass substrate by the sol-gel method. The photocatalytic activity of the samples was performed by means of the photodecomposition of methylene blue (MB) under visible light illumination. The FTIR results indicate that the samples present surface OH that are bound to the Ti and Fe and Zn atoms. The absorption edges are displaced toward to low energies as the concentration of Fe$_{2}$O$_{3}$ increases in TiO$_{2}$ and ZnO respectively. Here two mechanisms are observed during the photodecomposition of the methylene blue.