Carbon nanostructures by gas-phase laser pyrolysis

Carbon-made materials have been the field of major discoveries with the identification of new phases, which have stimulated a huge effort to understand their properties. Laser pyrolysis of hydrocarbons is based on a high temperature C/H/O/... system of well-established composition and allows obtaining carbon nanostructures from the almost amorphous carbon and particles with a turbostratic structure up to those characterized by a high degree of curvature. The variation of the gas composition and experimental parameters controls the final particle morphology providing useful functional properties. Gas-phase hydrocarbons were used either in resonant or non-resonant laser pyrolysis processes. The formation of different nanostructures is related to the presence of heteroatom in the reactants. Focusing, in the context of necessary presence of this heteroatom in the gas composition, on the present questions concerning the rational synthesis of nanostructures with controlled dimensionality, size and potentially properties, the work presents some significant changes in soot morphology produced by the variation of the experimental parameters and these, sometimes unavoidable, heterogeneous atoms.