Adsorption kinetics of NO2 on single-walled carbon nanotube thin-film sensor

The adsorption kinetics of NO2 on a single-walled carbon nanotube (SWNT) thin-film sensor was investigated. To avoid the influence of ambient air, the adsorption property of SWNTs was explored under high vacuum. By virtue of the suppression of the influence of residual gases and the cleanness of the SWNT surface in vacuum, the SWNTs exhibited high sensitivity with a detection limit of lower than 1 ppb. On the basis of the Langmuir adsorption isotherm, the sticking probability and adsorption energy of NO2 molecules on SWNTs were experimentally estimated. © 2008 The Japan Society of Applied Physics.