| Summary: | 博士 === 逢甲大學 === 化學工程學所 === 100 === Modification of metal oxide nanostructure and their application in sensors, catalysts and surface wettability were studied in this thesis. The first is the zinc oxide pore-array film prepared by microsphere lithography and electrochemical deposition (ECD). It has high specific surface area. It’s applications in the hydrophilic and hydrophobic switchable surface and light sensor were evaluated. The surface roughness of the pore-array film results in nearly super-hydrophobic characteristics are studied. Effects of the UV light and oxygen plasma treatment on the conversion and reversion of hydrophilic and hydrophobic characteristics. Pore-array surface structure lead to the light-trapping effect which enhance the light harvesting efficiency. Combined with the conjugated polymer such composite devices can be used as light sensors.
The second nanostructures are prepared by the growth of ZnO nanorods on the Al2O3 substrate with screen-printed platinum electrode, At first, the seed solution was ink-jet printed on the substrate. Then, the ZnO nanorods were selectively grown on the sensing area to make the nitrogen dioxide gas sensor. Due to high surface volume ratio of the nanorod structure, the gas detection sensitivity can be improved. These sensors with or without heat treatment exhibit N-type and P-type gas sensing characteristics respectively.
The third type is the hierarchical structure. At first, zinc oxide pore array was prepared by electrode chemical deposition. Then, the pore-array surface was modified by the growth of ZnO nanograss to increase the surface area. When exposed to the UV light, it can be used as photocatalyst for the decomposition of methyl orange dye. After the decoration of Ag nanoparticle on the hierarchical film, the decomposition efficiency can be improved furder.
The fourth is the gas sensor prepared by the combination of tin oxide nanoparticle with a HEMT (High electron mobility transistor). Tin oxide nano materials were produced by the hydrothermal method, and then coated on the gate region. Such sensors can be used in the sensing of hydrogen and oxygen at the low temperature.
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