SYNTHESIS OF CARBON NANOTUBES FOR ACETYLENE DETECTION

A gas sensor, utilizing carbon nanotubes (CNTs) in a pellet form for acetylenedetection has been developed. This research was carried out to investigate theabsorption effect of acetylene (C2H2) towards the change of resistance ofcarbon nanotubes pellet as sensor signal. Source Measurement Unit (SMU) wasused to study the gas sensing behaviour of resistance based sensors employingcarbon nanotubes pellet as the active sensing element. Studies revealed that theabsorption of acetylene into the carbon nanotubes pellet resulting in increase inpellet resistance. The changes are attributed to p-type conductivity insemiconducting carbon nanotubes. Carbon nanotubes used in this research wassynthesized by means of Floating Catalyst Chemical Vapor Deposition (FCCVD)method. Benzene was used as a hydrocarbon source while ferrocene as asource of catalyst with Hydrogen and Argon as carrier and purge gasrespectively. From the research, it was shown that carbon nanotubes show highsensitivity towards acetylene. The highest sensitivity recorded was 1.21, 1.16and 17.86 for S1, S2 and S3 respectively. It is expected that many applicationsof CNT-based sensors will be explored in future as the interest of thenanotechnology research in this field increases.