Synthesis Of Structure And Properties Of The Composite Of Several Metal Oxide Nanomaterials

In this thesis, the metal oxides of ZnAl2O4, MgO, ZrO2:Eu and YVO4:Eu were synthesized by a modified citrate precursor technique and a normal hydrothermal method, respectively. And their corresponding catalytic and optical properties were investigated.The first part is that a modified citrate precursor technique is developed for the preparation of porous metal oxides such as ZnAl2O4and NiO/MgO. In this technique, metal oxide was obtained by calcinations of a citrate precursor in inert atmosphere at 800℃, followed by annealing treatment in air at 400℃. The sample was characterized by X-Ray diffraction, transition electron microscopy and surface area analyses (BET method), and the results showed that the metal oxide had a high surface area of 230m2/g and controllable particle size from 5nm to 20nm by controlling the ration of citrate to metal cations and sintering temperature. The catalyst prepared based on the corresponding porous metal oxide show good catalytic activity, indicating that porous metal oxide as prepared is a promising catalyst support material.In the second part, nanocrystalline ZrO2:Eu and YVO4:Eu powders with different shapes were synthesized by a surfactant-assisted hydrothermal process. The structural and photoluminescence properties were investigated using the X-ray powder diffraction, transmission electron microscopy, and photoluminescence spectroscopy. Results showed that morphology could affect the emission intensity by the means of changing the symmetry of Eu sites in YVO4:Euand distributions of Eu in ZrO2:Eu, which cause the differences in activator capacity at thesurface.