Preparation of WO3/CNT nanocomposites and gas sensor application

• Main Authors: Te Tsun Pan, 潘德存
• Other Authors: Pi-Guey Su
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/66419998489485123037

碩士 === 中國文化大學 === 應用化學研究所 === 98 === Polyol process was combined with metal organic decomposition (MOD) method to fabricate a room-temperature NO2 gas sensor based on a tungsten trioxide (WO3) film and another a nanocomposite film of WO3/multi-walled carbon nanotubes (WO3/MWCNTs). X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the structure and morphology of the fabricated films. Comparative gas sensing results indicated that the sensor that was based on the WO3/MWCNTs nanocomposite film exhibited a much higher sensing sensitivity than that based on a WO3 film in the detection of NO2 gas at room temperature. Microstructural observations revealed that MWCNTs were embedded in the WO3 matrix. Therefore, a model of potential barriers to electronic conduction in the composite material was used to suggest that the high sensitivity is associated with the stretching of the two depletion layers at the surface of the WO3 film and at the interface of the WO3 film and the MWCNTs when detected gases are adsorbed at room temperature. The sensor that is based on a nanocomposite film of WO3/MWCNTs exhibited a strong response in the detection of very low concentrations of NO2 gas at room temperature and is practical because of the ease and low cost of its fabrication.