Residence time effect on fullerene yield in butadiene-based laser pyrolysis flame

A new route for fullerene synthesis by CO2-laser pyrolysis of gas phase mixture is proposed. Small hydrocarbon molecules which absorb the laser radiation, such as butadiene, are mixed with nitrous oxide (N2O) as oxidizer. Such a mixture allows avoiding the use of a photosensitizer as SF6 which causes contamination of the reaction zone and possibly influences the growth of fullerenic structures. This Letter also confirms the strong influence of the C/O atomic ratio in the mixture on the fullerene yield, and shows that residence time of the reactants in the pyrolysis flame and pressure influence dramatically the fullerene formation.