OATAO - Open Archive Toulouse Archive Ouverte Open Access Week

Preferential adsorption of NH3 gas molecules on MWCNT defect sites probed using in situ Raman spectroscopy

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

[img]
Preview
(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
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 - INPT (FRANCE)
Université de Toulouse > Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (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)
Laboratory name:
Statistics:download
Deposited By: cirimat webmestre
Deposited On:18 Jan 2018 10:19

Repository Staff Only: item control page