MATERIALS CHEMISTRY COMMUNICATION Nitrogen-containing carbon nanotubes

could be prepared by employing appropriate precursor molecules. Nanotubes containing both boron and nitrogen have Carbon nanotubes containing small amounts of nitrogen are been grown in the electric arc discharge between graphite produced by the pyrolysis of aza-aromatics such as pyridine, cathodes and graphite anodes filled with boron in a nitrogen methylpyrimidine and triazine over cobalt nanoparticles in an atmosphere.6 Such B x C y N z nanotubes have been recently preAr atmosphere; good yields of such nanotubes are obtained by pared by the pyrolysis of CH3CN5BCl3 at 1220 K over Co carrying out the pyrolysis of a mixture of pyridine and powder.7 In the present study, we have carried out the pyrolysis 5 in flowing Ar+H2 . of pyridine, 5-methylpyrimidine and s-triazine under reductive conditions at high temperatures in the presence of fine Co particles (ca. 50 nm diam.). Another strategy that we have employed is to carry out the pyrolysis of pyridine in the Carbon nanotubes are generally prepared by the arc evaporpresence of 5 , which provides the source of small iron ation of graphite1 or by the pyrolysis of hydrocarbons in the particles for the nucleation and growth of the nanotubes. presence of metal particles.2,3 Encouraged by the report that The procedure adopted for the pyrolysis of the aza-aromatics nitrogen-substituted 60 has been prepared,4,5 we were interwas as follows. Argon gas was passed through pyridine or 5methylpyrimidine at room temperature, and the gas mixture ested to explore whether carbon nanotubes containing nitrogen