Highly sensitive, room temperature gas sensor based on polyaniline-multiwalled carbon nanotubes (PANI/MWCNTs) nanocomposite for trace-level ammonia detection

• Published in: Sensors and actuators. B, Chemical Vol. 221; pp. 1523 - 1534
• Main Authors: Abdulla, Sukhananazerin, Mathew, Thalakkotur Lazar, Pullithadathil, Biji
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-12-2015
• Subjects: Ammonia; Carbon nanotubes; Chemiresistors; Gas sensors; Multi wall carbon nanotubes; Nanocomposite; Nanocomposites; NH3 gas monitoring; Polyaniline; Polymerization; Sensors; Spectroscopy; X-ray photoelectron spectroscopy; Carbon nanotubes; NH3 gas monitoring; Nanocomposite; Chemiresistors; Polyaniline; Gas sensors
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2015.08.002

•PANI/MWCNTs were synthesized by in-situ chemical oxidative polymerization method.•Uniform coating of PANI was observed onto the MWCNTs.•Enhancement in sensor properties was observed for PANI/MWNCT due to the uniform coating of PANI.•Rapid response and recovery time was observed for PANI/MWCNT nanocomposite.
Herein we report excellent gas sensor properties of Polyaniline functionalized multiwalled carbon nanotubes (PANI/MWCNTs) based nanocomposite for trace level detection of ammonia (NH3) gas. PANI/MWCNTs nanocomposite was synthesized by in-situ chemical oxidative polymerization of aniline monomer with carboxylated multiwalled carbon nanotubes (C-MWCNTs). The material was structurally characterized by UV–vis Spectroscopy, FT-IR Spectroscopy, Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and High Resolution Transmission Electron Microscopy (HRTEM). Uniform PANI layer with ∼7nm thickness was formed on the external walls of the MWCNTs. The gas sensor properties of C-MWCNT and PANI/MWCNTs nanocomposite towards NH3 gas exposure at trace level concentrations (2–10ppm) under ambient conditions were analyzed and their performances were compared. PANI/MWCNT nanocomposite based sensor exhibited excellent enhancement in sensor response and response/recovery characteristics with good reproducibility towards NH3 gas in comparison with C-MWCNT. The response and recovery time of the PANI/MWCNTs nanocomposite based sensor were found to be significantly improved in the order of a few seconds (6 s) towards NH3 gas. The results reveal the potential application of this sensor in monitoring trace level NH3 gas for varied applications.