Metal-decorated carbon nanotubes-based sensor array for simultaneous detection of toxic gases. Issue 1 (February 2021)

• Record Type: Journal Article
• Authors: Sharafeldin, Icell; Garcia-Rios, Sara; Ahmed, Nashaat; Alvarado, Miriam; Vilanova, Xavier; Allam, Nageh K.
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 1(2021)
• Publication Date: 2021-02
• Subjects: Gas sensor -- Carbon nanotubes -- Transition metal decoration; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2020.104534
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: Metal-decorated carbon nanotubes-based sensor arrays were successfully fabricated. CO and NO2 exposure showed the lowest and highest overall resistance change. Cu-decorated CNTs showed the highest resistance change response to H2 S gas. NH3 showed the highest response to Ru-decorated CNTs. DFT calculations enabled the in-depth understanding of the electron transfer mechanism. Abstract: Herein, we report a toxic gas detector based on an array of metal-decorated multiwalled carbon nanotubes (M-MWCNTs) sensors. The room temperature (20 °C) response of the sensors array towards NO2, H2 S, NH3, and CO gases was investigated. The MWCNTs were decorated with transition metals, Pt, Ti, Ag, Ru, and Cu to enhance the sensitivity and selectivity of the carbon nanotubes to the toxic gases. The M-MWCNTs powders were deposited on gold electrodes and printed on flexible Kapton sheets to form the sensors array. CO exhibited the lowest resistance change response for all six sensors (five transition metal-decorated MWCNTs sensors and one pristine MWCNTs-based sensor), with the Ag-MWCNTs sensor exhibiting the highest response of 0.047–100 ppm CO. The Ag-MWCNTs also revealed the relatively highest sensitivity of 0.944 upon exposure to 100 ppm NH3 . The Cu-MWCNTs sensor showed the highest sensitivity of 1.75 upon exposure to 10 ppm H2 S, while the Pt-MWCNTs sensor showed the highest response of 1.96 upon exposure to 10 ppm NO2 . A unique response pattern was generated for each gas that can be used for its identification. The experimental results were also compared to our previously reported density functional theory (DFT) calculations, revealing the same order of resistance change, thereby validating the use of DFT as a tool to predict the interaction properties and providing an in-depth understanding of the reducing/oxidizing gas electron transfer mechanisms.