Efficiency of Transition Metals in Combustion Catalyst for High Yield Helical Multi-Walled Carbon Nanotubes

Catalyst containing d-block transition metals were synthesised by combustion method and directly used as catalytic template to grow carbon nanotubes (CNTs) in Chemical vapour deposition (CVD) technique. The catalytic activities of these transition metals were studied and compared their efficiency to obtain high yield of CNTs. The morphology and structure of the carbon nanotubes are evaluated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), High resolution transmission electron microscope (HRTEM) and RAMAN spectroscopy. According to HRTEM the carbon nanotubes are multilayer helical shaped CNTs with smaller diameter between 4–5 nm. Raman spectra also suggest that the obtained CNTs are multiwalled with well graphitization. High yield was achieved because of very fine catalytic activity of Fe-Ni alloy rather than the other transition metal Co and Cu catalysts.