Multi-walled carbon nanotube-based gas sensors for NH3 detection

Multi-walled carbon nanotube (MWNT) based gas sensors for detecting gaseous molecules of ammonia (NH3) were developed. MWNTs were prepared using microwave plasma-enhanced chemical vapor deposition. The gas sensors, in which the nanotubes laid under the electrodes, were fabricated using electron-beam lithography and lift-off techniques. It is found that the conductance of MWNTs decreases when the sensors successively exposed to NH3 gas at room temperature of 25degreesC. The MWNT-based sensors are sensitive to NH3 gas. This suggests that the MWNTs could be a good candidate material for NH3 detection at room temperature. (C) 2003 Elsevier B.V. All rights reserved.