Potential application of multi-walled carbon nanotubes/activated carbon/bamboo charcoal for efficient alcohol sensing

Highlights: • In fabricated device, MWCNTs, bamboo charcoal or activated carbon was used as sensing material. • This fabricated device was used for alcohol (CH₃OH, C₂H₅OH and IPA) sensing. • Taking into account carriers tunneling between disordered regions alcohol detection explained. • Higher sensitivity was found for AC and BC in comparison to MWCNTs. • The fabricated device might be a cost effective for the detection of pure as well as dilute IPA. In the present work, multi-walled carbon nanotubes (MWCNTs), bamboo charcoal (BC) and activated carbon (AC) have been synthesized via thermal CVD technique by adopting fixed catalyst route and by simple pyrolysis, respectively. A two-terminal device has been fabricated using either MWCNTs, BC or AC as sensing material which was kept between the two terminals. This fabricated device was used for alcohol sensing at room temperature. In order to determine the sensitivity and detection limit, one droplet (∼10 μL) of alcohol (CH₃OH, C₂H₅OH and IPA) as well as IPA/water mixture was drop casted on the sensing material and the variation of resistance with respect to time has been monitored. The plausible explanation of detection has also been proposed taking into account the carriers tunneling between two disordered regions which was being wetted by alcohol molecules. We envision that the fabricated device might be a cost effective solution for the detection of pure as well as dilute isopropyl alcohol.