Etude des effets des dopants sur les propriétés physiques des films d’oxydes des métaux.

Abstract

This work is devoted to the study of the structural, morphological, optical and photocatalytic properties of thin layers of TiO2 un-doped and doped Lithium and Barium elaborated by the sol-gel method. The different samples are characterized by several investigation techniques: X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-Vis spectrophotometry. The XRD results showed that all films crystallized under anatase structure, and that the intensity of the diffraction peaks decreases with the doping (Li and Ba). The Rama spectra confirm the results obtained by XRD. The SEM results indicate that the undoped and Li-doped TiO2 films are homogeneous and without agglomeration over the entire surface of the sample. Roughness tends to increase when doped with lithium and decreases with barium. The characterization by UV-Visible spectrophotometer of all the films shows great transparency in the visible range. The band gap energy decreases with Li doping and increases with Ba. Photocatalytic tests are carried out on the degradation of the Rhodamine B under UV radiation. Show that the degradation efficiency of (RdB) of Ba-doped TiO2 thin films is greater than that of Li-doped TiO2 thin films.