Abstract Submitted to the    CCTN09 Symposium:

DFT study of the acid attack on carbon nanotubes walls

Iann C. Gerber, Frank Jolibois, Lionel Perrin, Romuald Poteau

INSA, UPS, CNRS, Universite de Toulouse, LPCNO 135 Avenue de Rangueil, F-31077 Toulouse, France

igerber@insa-toulouse.fr

VII. Chemical Modification of Nanotubes

Recent studies of metallic nanocatalysts supported by carbon nanotubes have shown very encouraging results concerning activity and selectivity in various type of chemical reactions [1] .
Before the deposit of metallic nanoparticles, the pretreatment of the nanotube walls by nitric acid appears to play a crucial role for the dispersion of the nanocatalysts, for the adsorption and the diffusion of the reactants [2]. We present here a theoretical study of this oxydation step, which corresponds to a functionalization of the nanotubes by oxygenated groups. We clearly demonstrate that vacancies strongly influence the oxydation of the graphitic surfaces, with stronger adsorption energies for -OH and -COOH groups. We further concentrate, by comparing molecular models and periodic boundary conditions results, on the reactivity of such defects. The early stages of the nitric acid attack will be presented, which correspond to a possible scenario for the disaggregation of the nanotubes, by the formation of carboxylic groups in the nearest-neighbourhood of vacancies.


[1] Nanocatalysis Edited by Ulrich Heiz and Uzi Landman. From the series: Nanoscience and Technology. Edited by P. Avouris, B. Bhushan, D. Bimberg, K. von Klitzing, H. Sakaki and R. Wiesendanger. Springer: Berlin, Heidelberg, New York, 2007.

[2] E. Roduner, Chem. Soc. Rev, 2006, 35, 583-592.

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