Multi-walled carbon nanotube sensor coupled with a pre- concentrator nanoporous layer for the detection of benzene at low temperature

Abstract : This work reports the development and study of a resistive gas sensor for benzene detection, based on multi-walled carbon nanotubes (MWCNTs). The MWCNTs were covered with a nanoporous SiO$_2$ layer whose function is to concentrate the pollutant in order to enhance the sensor performances. In this paper, we will describe the preparation of the sensor and highlight the beneficial effects of both the pre-concentration layer and the operating temperature. MWCNT/SiO$_2$-based sensors operating at 125°C are able to detect 50 ppb of benzene in air. Further developments are in progress in order to improve this detection limit.