%0 Journal Article
%T Interplay of interfacial compounds, catalyst thickness and carbon precursor supply in the selectivity of single-walled carbon nanotube growth
%+ Laboratoire Charles Coulomb (L2C)
%+ Laboratoire d'étude des microstructures [Châtillon] (LEM - ONERA - CNRS)
%+ CEA/LITEN/DTNM/LT
%A Navas, Hugo
%A Maruyama, Benji
%A Weaver, Kent
%A Paillet, Matthieu
%A Zahab, Ahmed Azmi
%A Fossard, Frederic
%A Loiseau, Annick
%A Quesnel, Etienne
%A Anglaret, Eric
%A Jourdain, Vincent
%< avec comité de lecture
%Z L2C:14-308
%@ 0008-6223
%J Carbon
%I Elsevier
%V 80
%P 599-609
%8 2014-12
%D 2014
%R 10.1016/j.carbon.2014.09.003
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Journal articles
%X This study is devoted to elucidate the interplay of catalyst thickness and growth conditions in the activation and selectivity of single-walled carbon nanotube growth using cobalt deposited on Si/SiO2 as a model system. In situ Raman studies reveal that thin catalyst layers require a higher pressure of carbon precursor to initiate nanotube growth. However, if the catalysts are pre-reduced, all catalyst thicknesses display the same low threshold pressure and a higher yield of single-walled carbon nanotubes. To explain these results, catalysts formed from a gradient of cobalt thickness are studied. Surface analyses show that during the catalyst preparation, catalyst atoms at the interface with silica form small and hard-to-reduce silicate nanoparticles while the catalyst in excess leads to the formation of large oxide particles. Weakly-reducing conditions of pretreatment or synthesis are sufficient to reduce the large oxide particles and to lead to the growth of large-diameter multi-walled carbon nanostructures. However, highly-reducing conditions are required to reduce the small silicate domains into small cobalt particles able to grow single-walled carbon nanotubes. These results show that reaction of the catalyst with the support to form more refractory compounds greatly impact the nucleation yield and the growth selectivity of single-walled carbon nanotubes.
%G English
%L hal-01201822
%U https://hal.science/hal-01201822
%~ CEA
%~ ONERA
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ LEM_UMR104
%~ GS-PHYSIQUE
%~ UM-2015-2021