Effect of Pt and Fe catalysts in the transformation of carbon black into carbon nanotubes

•We demonstrated the catalytic solid phase transformation of carbon black into nanotubes.•The effect of Platinum and iron metal nanoparticles as a catalyst in such transformation process is compared.•The effect of carbon blacks with different surface area and particle size in the nanotube formation is briefly studied.•The possibility of low temperature (400 °C) transformation is studied and growth mechanism is discussed briefly.

In this research carbon nanotubes and carbon nano onion-like structures were synthesized from carbon black using metal catalysts at 400 °C and 700 °C. Platinum and iron-group metals were used as catalysts for the transformation of CB into graphitized nanocarbon and the effect of both metals was compared. The synthesized products were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM) and Raman spectroscopy. The characterization shows that this process is very efficient in the synthesis of high quality graphitized products from amorphous carbon black, even though the process temperature was relatively low in comparison with previous studies. Distinguished graphitic walls of the newly formed carbon nanostructures were clearly visible in the HRTEM images. Possible growth difference related to the type of catalyst used is briefly explained with the basis of electron vacancies in d-orbitals of metals.