Carbon nanotubes with 1–6 walls have been grown on cobalt-loaded mesoporous silica (i.e., MCM41) by using acetylene catalytic chemical vapor deposition. It is found that titanium grafting on the MCM41 pore walls prior to cobalt loading promotes the ...
Carbon nanotubes with 1–6 walls have been grown on cobalt-loaded mesoporous silica (i.e., MCM41) by using acetylene catalytic chemical vapor deposition. It is found that titanium grafting on the MCM41 pore walls prior to cobalt loading promotes the growth of nanotubes with 1–6 walls. As-grown nanotube material is found to be a mixture of single-wall carbon nanotubes (SWNTs), double-wall carbon nanotubes (DWNTs) and thin-multiwall carbon nanotubes (t-MWNTs) with 3–6 walls. Annealing of the as-grown nanotubes has reduced the amount of SWNTs in the nanotube mixture. Several structural deformations of the t-MWNTs are observed during transmission electron microscopy (TEM) analysis. Complete or partial collapse of the t-MWNTs is also found due to these structural deformations. Graphite-like domains developed at the collapsed regions stabilize these structural deformations.