Single-walled carbon nanotubes synthesized by the pyrolysis of pyridine over catalysts

摘要

Single-walled carbon nanotubes (SWNTs) were successfully synthesized by pyrolysis of pyridine over MgO supported Fe-Mo or Co-Mo catalysts in the presence of pure H_2 or a mixture of H_2 and NH_3 atmospheres. The average diameters of SWNTs are - 1.5 and -3 nm for pure H_2 and the H_2 and HN_3 mixture, respectively. Scanning tunneling spectroscopy (STS) studies show that the SWNTs grown in both atmospheres are doped with nitrogen substituted into the lattice in a pyridine-type structure. This results in a donor feature in the local density of states with an energy that depends on the nitrogen doping concentration.