A novel approach to bulk synthesis of carbon nanotubes filled with metal by a catalytic chemical vapor deposition method

A novel microporous aluminophosphate (AlPO-5) support is reported for the first time as an alternative to the Na–Y zeolite support for large-scale production of carbon nanotubes using a cobalt metal catalyst which makes the separation and purification process of nanotubes easier. The use of an aluminophosphate support results in filling of the nanotubes with metal particles and metal nanowires while zeolite (Na–Y) support yields metal free nanotubes. This difference has been attributed to the difference in the mechanism of nanotube growth from electroneutral aluminophosphate and highly charged zeolite supports due to difference in the metal–support interaction in two cases.