Elaboration of single wall carbon nanotubes-based gas sensors: Evaluating the bundling effect on the sensor performance

In this article, carbon nanotube (CNT)-based sensors have been prepared using dispersion techniques. Sensors are obtained from a dispersion of CNTs using either chloroform as a solvent or sodium dodecylbenzene sulfonate as a surfactant. These sensors are prepared by drop-cast deposition of the solutions on interdigitated electrodes. The organic solvent processing leads to CNT layers where carbon nanotubes are obtained as larger bundles, whereas smaller bundles and individual tubes are predominantly formed in the surfactant processing. Under gas exposure (NO2), both sensors respond to low gas concentrations; however, the sensing layers composed of larger bundles of CNTs present a slightly different behaviour (in terms of rapid stabilisation and sensitivity) compared to those made of individual CNTs.

► Influence of bundling of carbon nanotubes on their gas sensing properties.
► Surfactant and CHCl3 dispersion methods enable to investigate on bundling effect.
► Presence of surfactant does not hinder the gas sensing ability of the nanotubes.
► Efficient debundling allows a higher number of adsorption sites and better response.