Etude et caractérisation des spinelles CuAl2O4 et MgAl2O4 synthétisés par différentes techniques.

Abstract

The work of this thesis is part of recent research concerning the development and characterization of nanometric oxides by different techniques. In view of the comparison with the many works already carried out of this important and still current subject, we were interested in the synthesis and the characterization of the two spinels CuAl2O4 and MgAl2O4 despite the complexity of the mechanisms involved in the Sol-Gel process. The first part was devoted to the structural characterization of CuAl2O4 and MgAl2O4 spinels but also to that of the mixed oxide CuAlO2. The characteristics of each of these bodies are explained according to the different synthesis conditions and the experimental means available. This work clearly establishes the nanoscale size of the three bodies. On the other hand, the presence of intermediate reaction phases has been demonstrated in the two spinels CuAl2O4, MgAl2O4. In the second part, we aimed to high light the role of pressure on pellets prepared from CuAl2O4 and MgAl2O4 powders calcined at 900°C for 4 hours. Following fine characterization techniques, this work has made it possible to observe structural modifications in the case of CuAl2O4 pellets. In the last part, we give a more technological application of the two spinels by studying the degradation of methylene blue by the two spinels.