Analysis of binary gas mixtures using chemiresistors based on carbon nanotubes (CNTs) networked films has been performed for chemical detection up to a sub-ppm level. The effects of individual interfering analytes of reducing H2S and NH3 gases on oxidizing NO2 gas adsorption in CNTs tangled films are considered. The CNTs are grown by plasma-enhanced chemical vapour deposition technology onto inexpensive alumina substrates, coated by cobalt nanosized catalyst. Charge transfer between adsorbed gas molecules and CNT networks, characterized by a semiconducting p-type electrical transport, occurs depending on opposite trend in the sensor response to the electron-donating interfering gases (H2S, NH 3) and target electron-withdrawing NO2 gas causing a compensation of the charge transport, upon given working conditions. This compensated exchange of electrical charge affects the limit of …
IOP Publishing Ltd.
1 Jan 2009
Volume: 42 Issue: 7
Journal Physics D: Applied Physics