Camphor-a botanical precursor producing garden of carbon nanotubes

Camphor, a botanical precursor, has been found to produce carbon nanotubes in large quantities; like a nanotube garden containing single-wall, multi-wall and aligned-nanotubes. These products grow as a result of thermal decomposition of camphor in argon atmosphere at 875(+/-25) degreesC. The novelty of this new precursor lies in the extremely low catalyst requirement for the realization of pure carbon nanotubes. Single-wall nanotubes are found in low quantity, whereas the yield of multi-wall nanotubes is as high as 90%. Moreover, vertically aligned nanotubes grow on large-area quartz substrates inserted in the reaction zone. Crystallinity of the as-grown nanotubes is fairly good, much better than that of those generally obtained by CVD using conventional hydrocarbons. Formation of amorphous carbon is almost nil, eliminating the need for post-deposition heat treatment. The presence of unwanted catalyst particles is extremely low. (C) 2002 Elsevier Science B.V. All rights reserved.