Catalytic synthesis of carbon nanotubes and carbon spheres using Kaolin supported catalyst

The substrate for the catalyst is important in chemical vapor deposition for carbon nanostructure synthesis. The importance of substrates in chemical vapor deposition has been explained here by using two different substrates such as Kaolin plate and ceramic plate. Kaolin supported cobalt catalyst was used on these substrates, also without substrate and the catalytic decomposition of C2H2 was carried out at the optimal temperature (750 °C) in nitrogen atmosphere. Two different kinds of carbon nanostructures, carbon nanotubes and carbon spheres, were obtained and their microstructure was investigated by transmission electron microscopy, high resolution transmission electron microscopy, X-ray diffractometer and laser Raman spectra. The influence of the catalyst substrate and the possible formation mechanism was discussed.