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Detection of a CO and NH3 gas mixture using carboxylic acid-functionalized single-walled carbon nanotubes

Ki-Young Dong1, Jinnil Choi3, Yang Doo Lee1, Byung Hyun Kang1, Youn-Yeol Yu1, Hyang Hee Choi2* and Byeong-Kwon Ju1*

Author Affiliations

1 Display and Nanosystem Laboratory, School of Engineering, Korea University, 5-1 Anam-Dong, Seongbuk-Gu, Seoul, 136-713, Republic of Korea

2 Department of Materials Science and Engineering, Yonsei University, Seoul, 120–749, Republic of Korea

3 Department of Mechanical Engineering, Hanbat National University, Daejeon, 305-719, Republic of Korea

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Nanoscale Research Letters 2013, 8:12  doi:10.1186/1556-276X-8-12

Published: 4 January 2013


Carbon nanotubes (CNT) are extremely sensitive to environmental gases. However, detection of mixture gas is still a challenge. Here, we report that 10 ppm of carbon monoxide (CO) and ammonia (NH3) can be electrically detected using a carboxylic acid-functionalized single-walled carbon nanotubes (C-SWCNT). CO and NH3 gases were mixed carefully with the same concentrations of 10 ppm. Our sensor showed faster response to the CO gas than the NH3 gas. The sensing properties and effect of carboxylic acid group were demonstrated, and C-SWCNT sensors with good repeatability and fast responses over a range of concentrations may be used as a simple and effective detection method of CO and NH3 mixture gas.

Gas sensors; Carboxylic acid functionalized; Single-walled carbon nanotubes; Mixture gas