Vapor Transport Synthesis of One-Dimensional Gallium Oxide Nanostructures for Photocatalysis
| Autor: | Wei-Tong Chen, 陳位同 |
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| Rok vydání: | 2010 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 98 With a vapor transport process, we have successfully synthesized one-dimensional β-Ga2O3 nanostructures by a high temperature tube furnace. The growth mechanism is followed by the vapor-liquid-solid (VLS) mechanism. The morphologies, crystal structures, chemical compositons, and optical properties of the as-synthesized β-Ga2O3 nanostructures were characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), photoluminescence (PL), cathodoluminescence (CL), and UV/visible spectroscopy (UV/visible). The photocatalytic activity were characterized by the degradation of rhodamine B and methylene blue solution. The results shows the as-synthesized β-Ga2O3 nanostructures are nanowires and nanosheets with monoclinic structure. Small angle lattice distortion exist in the β-Ga2O3 nanostructures confirmed by transmission electron microscope. The optical analysis shows four different luminescence bands: UV, deep blue, blue and green respectively. The oxygen vacancies (VO), gallium vacancies (VGa), and gallium-oxygen vacancy pairs (VGa−VO) of β-Ga2O3 is responsible for the emission in the blue-green region. The blue and green emission originates from the recombination of an electron formed by the oxygen vacancies (VO) and a hole formed by the gallium vacancies (VGa) or gallium-oxygen vacancy pairs (VGa−VO). The results show the β-Ga2O3 nanostructures are with superior luminescence property. Compared to TiO2, the photocatalytic activity of β-Ga2O3 nanostructures shows superior photocatalytic activity and extremely stable photocatalytic performance. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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