Carbon nanotubes with 2D and 3D multiple junctions

Multiple junction CNTs and 3D junction CNTs were obtained using a thermal chemical vapor deposition method without using a template substrate. The silicon substrates used were simply scratched using various types of abrasives prior to the growth of carbon nanotube. The hydrocarbon gas used was methane, which was balanced by hydrogen. A total of four catalyst precursors, Fe powders, Ni powders, FeS powders, and ferrocene, were used. It was found that only the use of ferrocene gave the formation of multiple junction CNTs. These multiple junction CNTs are found and suspended exclusively in the scratched striations. The mechanism of (multiple) junction CNT formation is discussed by addressing the role of the substrate and the catalyst.