Defect Engineering: Polycrystalline TiO2 Nanofibers with H2 Plasma Treatment Tuning Grain to Grain Boundary Potential for Optoelectrical Antibacterial - Agents
| Autor: | Pan, Pin-Chun, 潘品君 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Light to electric conversion photochemical effect can be achieved by using biocompatible material, polycrystalline titanium dioxide nanofibers (poly-TiO2 NFs). With versatility and low cost advantages, electrospinning process had been explored recently as means for preparing a wide variety of polycrystalline nanofiber materials for potential applications. Cell division and antibacterial issues were widely explored in recent research. However, as a large bandgap n type semiconductor, single crystalline TiO2 materials has the attribute of responding to UV light (400 nm). Due to the defect-rich structure, poly-TiO2 NFs can respond not only to UV light but also to visible light (wavelength between 400~550 nm). The photochemical effect can be significantly enhanced by using specific power hydrogen plasma treatment because plasma treatment can tune the barrier height between grains, surface potential and defect level. After such treatment, the soft energy light (long wavelength light, such as the red light (region wavelength between 620~730 nm)) can also be used in bio research (such as stimulating the cell growth or antibacterial growth). Recently, there are considerable interests in electrospun TiO2 NFs as antibacterial agents owing to their large grain to grain surface and the formation of reactive hydroxyl radicals (which can react with bacteria, cell membranes, and cellular proteins, leading to cell death). However, the photocatalytic effects of TiO2 NFs are relatively low due to the rich defect states. With H2 plasma treatment passivation, the surface potential of poly-TiO2 NFs was smoothened for electrons to transport. Consequently, the H2 plasma treated TiO2 NFs remained showed greater numbers of hydroxyl radicals and significantly enhanced visible light photocatalytic antibacterial activity. Based on these defect and interface engineering, poly-TiO2 NFs with hydrogen plasma treatment is a promising candidate for biological application. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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