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URN etd-0613107-190002 Statistics This thesis had been viewed 3095 times. Download 468 times. Author Cheng-Ming Zheng Author's Email Address No Public. Department Materials Engineering Year 2006 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 87 Title Synthesis of Hybrids Nanorod ZnO/MWCNTs for Gas Sensing Keyword gas sensing hydrothermal synthesis hybrid material MWCNTs nanorod ZnO nanorod ZnO MWCNTs hybrid material hydrothermal synthesis gas sensing Abstract In order to improve the disadvantage of MOS requiring operating at high temperatures, the developments of new type “hybrid material” are proposed. With new properties, “hybrid material” can detect the change of resistance at lower temperatures than pure MOS can.
One dimensional (1D) nano materials have properties of “signal conduction” and “high ratio of surface area to volume”, which are suitable for application of functional materials, such as gas sensors. “Hybrids of nanorod ZnO/MWCNTs” is one of the “hybrid materials”. In this study, the hybrids of nanorod ZnO/MWCNTs are prepared via hydrothermal synthesis at low temperature about 140℃. Then, the hybrids of nanorod ZnO/MWCNTs are analyzed by scanning electron microscope (SEM) for its surface morphology, transmission electron microscope (TEM) for its microscopic structure, and high resolution transmission electron microscope (HRTEM) for its microscopic structure at atomic scale. More accurate structure information can be obtained through X-ray diffraction (XRD). The analysis of the chemical compositions is mainly examined by energy dispersive spectroscopy (EDS).
MWCNTs after nitric acid treatment for 6 hours and hybrids of nanorod ZnO/MWCNTs gas sensors are compared in detecting system with various concentrations of NO2 gas (20, 40, 60, 80 and 100 ppm of NO2 in pure air) at different operative temperatures (50, 100, 150 and 200 ℃).
The results of gas sensing show that hybrid of nanorod ZnO/MWCNTs has higher sensitivities and better recovery properties than MWCNTs in NO2 gas detection.
Advisor Committee Hong-Ming Lin - advisor
Jyi-Tsong Lo - co-chair
She-huang Ｗu - co-chair
Ｗen-Chang Chen - co-chair
Files Date of Defense 2007-06-11 Date of Submission 2007-06-13