Preparation and Characterization of WO3 Powder by Hydrothermal Process
| Autor: | PIN-SYUAN CHEN, 陳品璇 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Tungsten Oxide (WO3) is a multifunctional inorganic metal oxide semiconductor material with good physical and chemical properties such as gas sensing, photocatalysis, photochromism, electrochromism, etc. in gas sensors and photocatalysts. The fields of electrochromic smart windows and photoelectrochemical devices have good application prospects. Nowadays, various physical and chemical synthesis methods have been used for the preparation of tungsten oxide, such as physical vapor deposition, chemical vapor deposition, thermal evaporation, sol-gel, hydrothermal, and the like. Among them, the hydrothermal method has the advantages of simple operation, easy control of reaction conditions, and various products with special morphologies. At present, the common forms of preparation of tungsten oxide powder by hydrothermal method include: nano particles, nano rods, nanowires, nanosheets and the like. In this study, sodium tungstate (Na2WO4·2H2O) was used as a raw material to prepare tungsten oxide (WO3) powder by hydrothermal synthesis. Various surfactants were added in the process, which were cetyltrimethylammonium bromide ( CTAB), sodium dodecyl sulfate (SDS), oxalic acid. In order to observe the effect of surfactant on particle shape, size and phase formation, the crystal form, microstructure, phase transition properties and properties of the powder were analyzed by XRD, SEM, Raman, FTIR and XPS. The surface morphology of the powder was observed by SEM. It was found that the surface of the tungsten oxide powder prepared in this experiment changed from a sheet structure without any surfactant to a spherical structure when oxalic acid was added, and the particle size changed from 200 nm to 100. In nm, the thickness also changes from 150 nm to 50 nm. The experimental results show that the tungsten oxide prepared in this experiment is heated by hydrothermal synthesis at 200 ° C for 24 hours, and the phase of tungsten oxide is obtained as a monoclinic structure by X-ray diffraction analysis, which is consistent with the literature results. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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