Effect of Hg2+ doping and of the annealing temperature on the nanostructural properties of TiO2 thin films obtained by sol-gel method

摘要

This work is a study of Hg2+-doped TiO2 thin films deposited on silicon substrates prepared by sol-gel method and treated at temperatures ranging between 600 to 1000 degrees C for 2 h. The structural and optical properties of thin films have been studied using different techniques. We analyzed the vibrations of the chemical bands by Fourier transform infrared (FTIR) spectroscopy and the optical properties by UV-Visible spectrophotometry (reflection mode) and photoluminescence (PL). The X-ray diffraction and Raman spectra of TiO2 thin films confirmed the crystallization of the structure under the form of anatase, rutile, mercury titanate (HgTiO3) as a function of the annealing temperature. The observation by scanning electron microscopy (SEM) showed the changing morphology, with respect to nanostructures, nanosheets, nanotubes, with the annealing temperature. The diameters of nanotubes ranged from 50 nm to 400 nm. The photoluminescence and reflectance spectra indicated that these structures should enhance photocatalytic activity. (C) 2014 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.