Characteristization of TiO2 Nanoparticles
| Autor: | Sung-yen Wei, 魏松煙 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 In this study, we tried to synthesize different phases TiO2 nanoparticle crystals by adjusting the pH value of the TiCl4 solution through the hydrolysis and condensation reaction at the room temperature, these products then treated with thermal process in different ambience and temperature. In order to measure variation of the crystalline property, surface morphology and optical properties of the different phases TiO2 nanoparticles, these particles were finally analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), utraviolet-visible spectrometer (UV) and photoluminescence spectrometer (PL). From XRD analysis, the results appeared that the first order crystal diameter of these TiO2 nanoparticles were affected by the variation of the experiment parameter, the crystal diameter increased with the increasing of the oxygen concentration and the annealing temperature but decreased at 450℃ high vacuum ambient environment. In optical properties, we could obviously find that the indirect band gap varied with the different ambiences from the absorption spectrum, it existed a blue shift phenomenon at the high vacuum thermal process environment. In the other hand, we could also find that there was a obviously blue shift on the direct band gap of the 550℃ high vacuum thermal process one. Eventually, the emission spectrum revealed that there existed a great quantities of oxygen vacancies of particles at the high vacuum condition, the vacancies had a strong emission light at the 465nm and 540nm wavelength. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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