Pyrolytic Synthesis of Conical Carbon Fibers with Carbon Nanotube Tips on Carbon Substrates

摘要

The pyrolytic synthesis of conical carbon fibers (CCFs) with tips of carbon nanotubes (CNTs) that ran through the CCFs as their cores has been investigated under different experimental conditions. The core construction of the carbon composite was found to be mainly determined by the presence of a nickel catalyst and the use of a high reaction temperature of 1800 ℃. The graphon (a graphitized carbon black) and pyrolytic carbon film substrate make a greater contribution to the nucleation of the CCF and CNT composites than the basal surface of highly oriented pyrolytic graphite with a deposit of nickel. Raman spectra show that the two former substrates have many more sp~2 defects than the latter. The size of the CCFs was determined by the concentration of carbon atoms during growth, which could be controlled by adjusting the temperature and etching hydrogen flow.