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.