Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)


Accueil > La Recherche > Axes & Equipes > Nanostructures & Spectroscopies > Equipe : Nanomatériaux > Thème : Elaboration et étude de réseaux, films et composites à base de nanotubes

Mechanisms of CNT growth and deactivation

par Sébastien LAYSSAC - publié le , mis à jour le

Involved researchers : M. Picher (PhD), E. Anglaret, V. Jourdain

Carbon nanotubes (CNTs) are commonly synthesized by Chemical Vapor Deposition (CVD) assisted by catalyst nanoparticles. The grown samples are usually a mixture of nanotubes with different structural features in terms of diameter, chiral angle, length, position and orientation. This lack of control is the major bottleneck in the development of CNT-based technologies.
To elucidate the mechanisms of CNT growth and deactivation that control the CNT length, we develop an approach based on in situ Raman measurements to obtain qualitative and quantitative information on the growth kinetics of single-walled CNTs [1]. Our studies shows that the growth rate and the growth lifetime are inversely correlated and display two different regimes as a function of the growth conditions. Activation energies are measured for the growth rate and the lifetime and compared to the activation energy measured for the healing of defects during the growth. From these experimental results, we propose a model of the elementary steps of the nanotube growth where the self-deactivation results from an accretion of defects at the interface between the catalyst nanoparticle and the open edge of the nanotube. Annealing of these edge defects is the key for prolonging the growth lifetime and obtaining long CNTs.

[1] M. Picher et al., Nano Lett. 9, 542 (2009) - © L2C

© L2C

Funding : ANR P-NANO "T-Nice", ANR P3N "SOS Nanotubes"