Investigation on the Best Conditions for Purification of Multiwall Carbon Nanotubes

Abstract

Multiwall carbon nanotubes (MWCNTs) were synthesized using cyclohexanol, ferrocene and nitrogen as carbon source, catalyst and carrier gas, respectively. Carbon nanotubes purification was performed by oxidation and acid treatment. Characterization of carbon nanotubes before and after purification was carried out using SEM, TEM and Raman spectroscopy and show that purification can reduce amorphous carbon and metal particles significantly. Furthermore, different acid treatment [HNO₃/H₂SO₄ (1/3), (c) HNO₃/H₂SO₄ (1/1), (d) 8M HCl and (e) 8M HNO₃] demonstrated that 8M HNO₃ can decrease impurities without destroying the structure of carbon nanotubes.