Preparation And Prorerties Of Oxides Nanoparticles

In this dissertation, the anatase TiO2 with different morphologies, SnO2 with hemi-tube structures and porous BaSO4 microspheres had been prepared by hydrothermal method. The prepared samples were characterized by different methods, such as X-ray Diffraction (XRD), Transmission Electron Microscopy(TEM) and Scanning Electron Microscopy (SEM). The degradation of methyl orange was used as a model reaction to test the photocatalytic activity of the samples. The growth mechanisms for nanocrystals with different morphology were discussed and the influencing factors of experimentation on the degradation of methyl orange were also analysed.The experimental results show that anatase TiO2 with different morphologies can be prepared by hydrothermal method under varied conditions when Ti(SO4)2 was used as precursor, the type of heating and surface modifier were important factors for formation of different shaped nanoparticles and the addition of ethanol can also influence the shape and the photocatalytic activities of the formed nanoparticles. The monodisperse rice-like TiO2 nanoparticles had been prepared, when type of heating was changed, PVP as surface modifier, with adding H2O2. The surface of these nanoparticles is very rough. The lengths and widths of rice-like TiO2 nanoparticles are 200 nm and 120 nm, respectively. The ellipsoidal TiO2 nanoparticles had been prepared using H2O and ethnol as solven. The long axis and short axis of ellipsoidal TiO2 nanoparticles are in the range of 55～85nm and 50～60nm, respectively. The ellipsoidal TiO2 nanoparticles showed high photocatalytic ability. The specific surface of ellipsoidal TiO2 nanoparticles area is 127.52m2/g. The Ag-TiO2 hollow structure were prepared by hydrothermal method at 150℃, using Ti(SO4)2 as precursor, CTAB as surface modifier, adding AgNO3 and H2O2. The diameter of Ag-TiO2 hollow structure is in the range of 400～600 nm. The prepared Ag-TiO2 hollow structure showed a high performance in antibacterial activity. The flower-like TiO2 were prepared through the hydrothermal hydrolysis of Ti(SO4)2, adding H2O2.TiO2 hollow microspheres were prepared by hydrothermal method at 170℃using titanium tetrachloride as the precursor, oxalate ions as surface modifier, adding AgNO3 and H2O2. The diameter of TiO2 hollow microsphere is about 4μm. The experimental results show that 2% Fe3+ dope TiO2 hollow microsphere showed high photocatalytic ability with dosage is 50 mg/L.SnO2 nano-(micro-) structures have been prepared through the hydrothermal oxidation of SnCl2 using aspartic acid as surface modifier. The influence of various experimental parameters on the morphologies of SnO2 has been investigated. Photoluminescence property has been studied and possible growth mechanism of SnO2 hemi-tubes has been discussed.Monodisperse porous BaSO4 microspheres, have been successfully prepared by a simple hydrothermal process in the presence of poly-(vinylpyrrolidone) (PVP) at 170°C.The BaSO4 porous microspheres have uniform size and diameter of 550 nm.