Fabrication and characterization of carbon nanotube based high sensitive gas sensors operable at room temperature

Multi-walled carbon nanotubes (MWCNTs) were prepared using both dc sputtering method and thermal CVD method. Single-walled carbon nanotubes (SWCNTs) were prepared by pulsed laser ablation (PLA) method. CNT based NOx gas sensors which can operate at low temperature were fabricated. Both MWCNT thin films and SWCNT thin films were grown on Al2O3 substrate with interdigitated Pt-electrodes to make a gas sensor. Gas sensing properties to NO and NO2 gases were measured. Resistance of the prepared CNT-based gas sensor decreased with increase of NO and NO2 gas concentration. The SWCNT-based gas sensor showed higher sensitivity and rapid-response to the test gas. (C) 2008 Elsevier B.V. All rights reserved.