奈米碳管與二氧化鈦混成系統之合成研究

The Synthesis of Nano Hybrid CNTs/TiO2 Materials

楊慶鴻(Ching-Hong Yang)

指導教授 ： 林鴻明

大同大學/工程學院/材料工程學系所/碩士(2004年)

摘要

近年來奈米碳管由於具有獨特的性質例如：高的長直比、超強的強度、奈米級的結構、儲氫能力和半導體的性質。更由於未來未知領域的開發，使奈米碳管已經變成一種越來越受歡迎的材料並廣泛的成為研究對象。本研究係探討二氧化鈦包覆碳奈米管之特性，使其成為一個新的材料，這個新材料具有碳奈米管與二氧化鈦的雙重特性優點，可以探討其特殊機械性質、氣體感測、電性等特性，論文中有初步對混成材料的電性研究數據，同時希望利用碳管比表面積大、可供給眾多氣體吸附位置、具良好導電性等特性，使新材料能在室溫下導通，並成為一個能在室溫下偵測的氣體感測器。
實驗是以溶膠凝膠法製備二氧化鈦,以鈦酸異丙脂有機溶液為前驅物，並混不同濃度之異丙醇，加入數滴甲醇來分散與控制粒徑，之後與不同濃度奈米碳管混合，加入去離子水水解聚合反應後，將混配好的溶液以旋轉塗佈的方式生成TiO2/CNTs薄膜。在室溫下乾燥後，接著以400°C溫度燒結, 在材料鑑定方面，以SEM 、TEM、Raman、XRD、AFM、電性量測系統等儀器來分析膜的成分、結構與表面型態以及電性特性。
實驗結果顯示，本實驗以溶膠凝膠法合成的二氧化鈦可成左漸]覆奈米碳管，並呈現二氧化鈦如珍珠項鍊狀附在碳管上的型態，電性量測顯示出二氧化鈦與碳管合成後降低了感測器的操作溫度，使實驗在室溫下對一氧化碳氣體即有感測效果。

關鍵字

溶膠凝膠法.二氧化鈦.奈米碳管

並列摘要

In recent years, carbon nanotubes have become intriguing materials, and have been studied in many fields of their unique properties such as high ratio of length to diameter, super strength, nano-scale structure, hydrogen storage, property of semiconductor and unknowable fields. In this experiment, the elaboration of an inorganic matrix containing embedded carbon nanotubes leads to a new nanocomposite. The possible applications of this CNTs nanocomposite are the intrinsic mechanical or electrical properties and gas sensing etc. In the study, the electrical properties of the new nanocomposite material have been examined. The carbon nanotubes provide the large surface area that can enhance the adsorption properties of gases and the conductivity at the room temperature for gas sensing.
In this study, TiO2 is prepared by sol-gel technique. The precursor was obtained by mixing titanium tetraisopropoxide and isopropyl alcohol. After mixing, the CNTs add and mix in the sol-gel solution. The methanol and deionic water are used to control the particle size and precipation of TiO2. Thin films of TiO2 and CNTs/TiO2 were deposited by a spin-coating method onto pre-cleaned silicon and alumina substrates. The CNTs/TiO2 thin film calcined in an electric furnace in air to 400℃. SEM, TEM, XRD, AFM and Raman instruments were examined the compositional and structural properties of these specimens.

Experiments results show the successful coating of TiO2 on the surface of carbon nanotubes by a sol-gel method. The surface morphology of TiO2 coated CNTs are likes the pearl necklace structure. The process of CNTs-hybridization shows the decreasing the sensing operation temperature and the enhancement the gas sensitivity for detecting CO gas at room temperature.

並列關鍵字

CNTs ； sol-gel ； TiO2

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