Transformation of carbon black into carbon nano-beads and nanotubes: the effect of catalysts

Structural transformation of carbon black (CB) into carbon nano-beads and nanotubes was achieved at 1000 °C using ferrocene and nickelocene as catalyst precursors using a simple and single step chemical vapor deposition method. The samples were characterized by XRD, SEM, TEM, HR-TEM and Raman spectroscopy. Results indicate that different morphological and high quality nano carbon structures were obtained using different weight ratios of catalyst to precursor. The use of bimetallic catalysts provides many different morphologies and a higher degree of crystal order of the carbon nanostructures than the use of mono-metallic catalysts. The nanotubes were mostly filled with metal nanoparticles and the degree of metal-filling is dependent on the weight ratio of catalyst precursor to CB. Metal-filled multi-walled carbon nano-bead structures with a high degree of crystalline order are also obtained at weight ratios of CB: ferrocene: nickelocene of 1:2:2.