Pure and aligned carbon nanotubes produced by the pyrolysis of benzene-based aerosols

The present work reports a method for preparing nanotubes involving pyrolysis of aerosols generated from benzene solutions of metallocenes. Different concentrations of ferrocene or ferrocene/nickelocene mixtures (65:35 and 25:75 Fe:Ni atomic ratios) were atomised with a compressed gas (Ar) driven sprayer, and pyrolysed at 8(H) or 950degreesC. The black products, analysed by SEM, (HR)TEM, and XRD, consisted of carpet-like aligned multi-walled nanotubes which are partly filled. The purity of the samples is generally high, but is drastically improved by using a ferrocene/nickelocene mixture 65:35 Fe:Ni. The changes in the nanotube size, and in the degree/size of filling, are reported as a function of synthesis parameters such as the nature and content of the metallocene, and the pyrolysis temperature