Growth of carbon nanotubes with different morphologies by pyrolising acetylene

Abstract

Multiwalled carbon nanotubes (MWCNTs) with different morphologies have been prepared by pyrolysis of a mixture of acetylene-ferrocene over predeposited Co and Ni catalysts at 700°C. A high yield of carbon nanotubes with further purification have been obtained in the optimal conditions. The optimum synthesis parameters included synthesis temperature of 700°C, growth time of 30?min, flowrate of acetylene and hydrogen of 40 and 300?sccm respectively. Multiwall straight, curved, helically, coiled, planar-spiral and V-shaped nanotubes were found with diameters in the range of 10-70?nm and with lengths up to 5?μm. The morphology and structure features of the MWCNTs are characterised using scanning electron microscopy, transmission electron microscopy, energy dispersive spectra, Raman spectroscopy and thermogravimetry analyses.