Chiral vector and metal catalyst-dependent growth kinetics of single-wall carbon nanotubes

Abstract

Single-wall carbon nanotubes (SWCNTs) are synthesized by the pyrolysis of cobaltocene and nickelocene in the interior of hosting SWCNTs. In situ Raman spectroscopy elucidates growth kinetics of SWCNTs of nine different chiral vectors (8,8), (12,3), (13,1), (9,6), (10,4), (11,2), (11,1), (9,3) and (9,2) that features faster and slower growth rates. The activation energy of the faster growth increases monotonically with the SWCNT diameter, while that of the slower growth doesn't show a clear dependence, and neither of them depends on the chiral angle. At a given temperature the growth rates of the inner tubes are much higher with nickel than those with cobalt. The activation energy of the faster growth is found to be independent of the metal type, whereas that of the slower growth is metal-specific. The information obtained in the present study is elemental for a large-scale and selective synthesis of single-chirality SWCNTs that are demanded for applications.