Etude des nanoparticules de dioxyde de titane élaborées par voies chimiques

Abstract

"This work involves the elaboration and characterization of nanopowders of titanium dioxide TiO2 prepared by solvothermal, hydrothermal and sol-gel methods. At first, we prepared TiO2 nanopowders by hydrothermal method assisted by micro-waves, and then these powders were treated in an alkaline medium of NaOH, in aim to change their morphology. Secondly we modified the initial concentration of the precursor and the irradiation time in goal to obtained nanoparticles with a small grain size in a short reaction time, after the powder was treated at different hydrothermal temperature. Finally we did study the effect of doping on the characteristics of our samples prepared by both technics (hydrothermal and sol-gel). For this, various structural and spectroscopic investigation technics were used (DRX, MEB, IR, Uv-Visible and PL). The results shows that it is possible to modify the morphology of TiO2 nanopowder (nano-flower, nano-rood, nano-sphere ...) prepared by the hydrothermal method assisted by microwave or conventional hydrothermal method. After studying the effect of irradiation time and precursor concentration, we figure out the optimum conditions for obtained the nanopowders in a short time that is to say, minimized energy consuming. The obtained result shows the effect of doping on the phase transformation (anatase-rutile) at low temperature."