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DWCNT-Doped Silica Gel Exhibiting Both Ionic and Electronic Conductivities

Le Ouay, Benjamin and Lau-Truong, Stéphanie and Flahaut, Emmanuel and Brayner, Roberta and Aubard, Jean and Coradin, Thibaud and Laberty-Robert, Christel DWCNT-Doped Silica Gel Exhibiting Both Ionic and Electronic Conductivities. (2012) The Journal of Physical Chemistry C, 116 (20). 11306-11314. ISSN 1932-7447

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Official URL: http://dx.doi.org/10.1021/jp2115669

Abstract

Silica gels doped with double-walled carbon nanotubes (DWCNTs) were prepared using an aqueous sol−gel route in mild conditions (neutral pH, room temperature). The wet gels exhibited both ionic and electronic conduction. Electrochemical impedance spectroscopy was used to study these two different conduction pathways that prevail at different characteristic time scales. The ionic conduction in the silica network was found to be independent of the DWCNT-doping rate. The electronic conduction through the DWCNT network was found to occur above a critical concentration (0.175 wt %) corresponding to nanotube percolation threshold. The highest content in DWCNTs (0.8 wt %) exhibited a conductivity of 0.05 S/m. Furthermore, the DWCNTs network was found to evolve even after the macroscopic solidification of the gel, suggesting a reorganization of the DWCNTs at the molecular level. This phenomenon could be attributed to the polarization effect of the electrode and was confirmed by Raman spectroscopy studies. Such materials can be useful for the design of sensors incorporating electroactive chemical or biological species.

Item Type:Article
Additional Information:Thanks to American Chemical Society editor. The definitive version is available at http://pubs.acs.org/. The original PDF of the article can be found at The Journal of Physical Chemistry C website : http://dx.doi.org/10.1021/jp2115669
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Collège de France (FRANCE)
Other partners > Ecole Nationale Supérieure de Chimie de Paris - ENSCP (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Other partners > Université de Paris Diderot - Paris 7 (FRANCE)
Other partners > Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Other partners > Ecole Pratique des Hautes Etudes - EPHE (FRANCE)
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Deposited By: cirimat webmestre
Deposited On:03 May 2013 13:45

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