Mortazavi S.Z.,Materials Research School NSTI |
Novinrooz A.J.,Materials Research School NSTI |
Reyhani A.,Materials Research School NSTI |
Mirershadi S.,Materials Research School NSTI
Central European Journal of Physics | Year: 2010
Multi-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs' diameter. © 2010 Versita Warsaw and Springer-Verlag Berlin Heidelberg.