Synthesis of multi-walled carbon nanotubes (MWNTS) over anodic aluminium oxide (AAO) template

Currently ordered carbon nanotube (CNT) arrays are generally prepared using the template synthesis method. The template synthesis method can improve the selectivity and uniformity of CNTs. Therefore in this study, the AAO templates were applied as the catalyst support to synthesize CNTs in high yield and cost saving by controlling the CNTs characteristics and morphologies. A practical and high performance CCVD system was designed and built to carry out the pyrolysis of hydrocarbon to produce the multi-walled carbon nanotubes (MWNTs). The supported catalysts of cobalt (Co), iron (Fe) and mixture of Co and Fe were prepared using the AAO template as the support. The AAO supported catalysts were prepared using the wetness impregnation method. The characterizations of the MWNT yields were carried out using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) as well as Energy Dispersive X-ray Analysis (EDX). The AAO supported catalysts prepared were found capable of producing good quality MWNTs and generated carbon content as high as 86.5 wt%. The as-grown MWNTs showed high degree of graphitization, purity and density with configurations of bundles, arrays and coils.