Carbon nanotubes and its gas-sensing applications: A review

The paper presents a substantial review of the work done on the design and development of different types of gas sensors using Carbon Nanotubes. The fundamental techniques of preparation of Carbon Nanotubes have also been reported here. The variety of sensors, their detection processes of a range of gases including NO2, H2S, C2H5OH, and others have been described here. Single-Walled and Multi Walled Carbon Nanotubes in their pristine and amalgamated forms has been used and to develop a range of sensing devices. It also presents a comparative study on each gas giving the fundamental parameters like the limit of detection, the range of concentration and response time to differentiate their capability regarding the materials used to fabrication them to detect the gases. Finally, the challenges related to the currently available Carbon Nanotubes-based gas sensors, their associated remedial actions and some of the possible opportunities for future work are elucidated in the paper. (C) 2019 Elsevier B.V. All rights reserved.