Abstract
Carbon nanomaterials have been attracting a great deal of research interest in the last few years. The presented work in our article reports the fabrication of three types of multiwalled carbon nanotubes (MWCNTs) film sensors namely: as-synthesized nickel catalyzed MWNTs film sensor, MWNTs deposited with platinum (Pt) nanoparticles film sensor and MWNTs deposited with Pt nanoparticles film sensor annealed at 400 degrees C for one hour. The carbon mono-oxide (CO) gas sensing properties of all these three types of MWCNTs film sensors have been studied. A very thin layer (5 nm) of Pt nanoparticles has been deposited on this MWCNTs film. Gold electrodes have thermally been evaporated to get the characteristic pattern of MWCNTs film sensor. We found a typical response of MWCNTs gas sensor at four different concentration (200, 400, 600 and 800 ppm) of sensing gas. The resistance of fabricated MWCNTs film sensor increases with increase in the gas concentration whereas the sensitivity and responsiveness of the sensing film show a decreasing trend with increase in the concentration of CO gas. Our studies show a good response to the sensing CO gas with a fast recovery time. Dependence of conductivity on temperature has also been studied to explain the electrical properties of these MWCNTs film sensors.