Chimowa, George and Matsoso, Boitumelo and Coville, Neil J. and Ray, Suprakas Sinha and Flahaut, Emmanuel
and Hungria, Teresa and Datas, Lucien
and Mwakikunga, Bonex W.
Preferential adsorption of NH3 gas molecules on MWCNT defect sites probed using in situ Raman spectroscopy.
(2017)
Physica Status Solidi A, 214 (10). 1-7. ISSN 1862-6300
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(Document in English)
PDF (Author's version) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader 680kB |
Official URL: http://doi.org/10.1002/pssa.201600930
Abstract
The preferential adsorption of NH3 gas molecules on multiwalled carbon nanotubes (MWCNTs) was studied using in situ Raman spectroscopy. It was observed that the full widths at half maximum of the G band and the intensity ratio I2D/IG of the MWCNTs decreased significantly during NH3 gas adsorption at elevated temperatures. These observations were explained in terms of suppressed second-order-defect associated Raman vibrations resulting in a lower disorder Raman band due to ammonia adsorption on the defect sites. Another corresponding effect was a temporary increase in electron doping levels due to ammonia adsorption. This behaviour was accompanied by a drop of ca. 2% in the resistance of the MWCNTs corresponding to the occupancy of most of the defect sites. We suggest preferential adsorption of ammonia gas molecules on the thermally activated defect sites of MWCNTs as an appropriate gas sensing mechanism. This knowledge can be used to design and tune the selectivity of ammonia gas sensors
Item Type: | Article |
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Additional Information: | Thanks to Wiley-VCH Verlag editor. The original PDF of the article can be found at Physica Status Solidi A website : http://onlinelibrary.wiley.com/doi/10.1002/pssa.201600930/abstract |
HAL Id: | hal-01687165 |
Audience (journal): | International peer-reviewed journal |
Uncontrolled Keywords: | |
Institution: | French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE) Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE) Université de Toulouse > Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE) Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE) Other partners > University of Johannesburg - UJ (SOUTH AFRICA) Other partners > University of Pretoria (SOUTH AFRICA) Other partners > University of the Witwatersrand - WITS (SOUTH AFRICA) |
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Deposited On: | 18 Jan 2018 10:19 |
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