Hydrothermal Synthesis of Oxide Hollow Spheres
|School||Harbin Institute of Technology|
|Keywords||hydrothermal synthesis template method hollow spheres spheral cage spheral core/shell structure|
This thesis focuses on the preparation of several functional materials, including SnO2, ZnO, NiO and ATO spheres with hollow structures, by template method and hydrothermal method employing glucose and metal salts as the starting materials. The as-obtained products were characterized by XRD, SEM, TEM, FTIR, TG-DTA and BET techniques. The formation mechanism of oxide hollow spheres was also studied. The main results are summarized as follows:Carbon spheres were fabricated under hydrothermal condition of low temperature （160180℃） with glucose as the carbon precursor, and under condition of neutral and nearly neutral. The diverse morphologies cabon spheres with the size in the range of 180800nm could be obtained by the hydrothermal reaction at 180 degree celsus for 68 hours, with weight ratio of the glucose to distilled water is 1:10.The carbon spheres were then used as template for fabricating SnO2 hollow spheres, which with the size in the range of 100150nm and the thick of no more than 25nm were gotten.SnO2 hollow spheres and spheral core-shell structure were then synthesized by the hydrothermal method, glucose and SnCl4 were used as reactants. It was found out that concentration of reactants significantly affects the SnO2 hollow structures.Sb-doped SnO2 （ATO） hollow spheres were also synthesized by the hydrothermal method. The XRD shows that the existence of Sb is trivalency. The SEM analysis shows that the doping has an influence on the ATO hollow structures.ZnO hollow spheres and spheral cage structure were also synthesized by the hydrothermal method with glucose and ZnCl2 as reactants. Preparation of NiO spheral core-shell structure was also performed by the hydrothermal method with glucose and NiSO4 as reactants.