混成針狀奈米氧化鋅/奈米碳管之合成 與氣體感測性質研究

Synthesis of Hybrids Nanorod ZnO/MWCNTs for Gas Sensing

鄭承明(Cheng-Ming Zheng)

指導教授 ： 林鴻明

大同大學/工程學院/材料工程學系所/碩士(2007年)

摘要

為了改進傳統金屬氧化物半導體只能在高溫時操作的缺點，新型態的「混成材料」被發展出來。結合新特性的混成感測材料可以在較低溫度時偵測到氣體時之電阻值的變化。
一維的奈米材料具有「訊號傳導」與「高比表面積」之特性，適合發展於功能性應用方面，例如氣體感測元件。“奈米針狀氧化鋅和多璧奈米碳管的混成材料”即為一維奈米混成材料。本研究將利用水熱法，在140℃熱處理溫度，製備奈米級針狀氧化鋅與多壁奈米碳管的混成材料，並藉由EDS、XRD、SEM、TEM、HRTEM的檢測，對於混成材料進行成份分析、表面形態及內部結構的觀察。
本實驗分別對於奈米針狀氧化鋅/多壁奈米碳管的混成材料以及多壁奈米碳管，於不同溫度、不同NO2氣體濃度時進行感測性質之比較。實驗結果顯示，奈米針狀氧化鋅和多壁奈米碳管的混成材料相較多壁奈米碳管具有更高的靈敏度與較佳的回復性質。

關鍵字

奈米針狀氧化鋅 ； 多壁奈米碳管 ； 混成材料 ； 水熱法 ； 氣體感測

並列摘要

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.

並列關鍵字

nanorod ZnO ； MWCNTs ； hybrid material ； hydrothermal synthesis ； gas sensing

參考文獻

[15] E. Ivers-Tiffee, K. Seitz, Am. Ceram. Soc. Bull. 66 (1987) 1384.

[50] Changlong Jiang, Wangqun Zhang, Guifu Zou, Weicao Yu, and Yitai Qian J. Phys. Chem. B (2005) 109, 1361-1363.

[7] Wei-Jen Liou, Tsung-Yeh Yang, Kuang-Nan Lin, Ching-Hong Yang, -Ming Lin, "Sensing Properties of CNT hybrid MOS-based Sensors," Materials Research Society, Vol. 828, pp. A2.6.1-A2.6.11, (2005).

[95] Hongyan Xu, Xiulin Liu, Deliang Cui , Mei Li, Minhua Jiang, Sensors and Actuators B 114 (2006) 301–307.

[87] Tetsuro Seiyama, Akio Kato, Kiyoshi Fujiishi, and Masanori Nagatani, AnalyticalChemistry, 34 (1962) 1502-1503.