Production of iron-oxide nanoparticles by laser-induced pyrolysis of gaseous precursors

Abstract

Laser-assisted pyrolysis in a continuous flow reactor has been applied to synthesise iron-oxide nanoparticles. The scope of the present contribution was to investigate the possibility of increasing the reaction yield in order to obtain powder amounts suitable for practical applications. To this aim, a gas mixture containing Fe(CO) 5 and N 2O has been submitted to CO 2 c.w. laser pyrolysis. As a reaction sensitiser gas, SF 6 has been preferred to C 2H 4 to avoid ethylene fragmentation in N 2O presence and the formation of iron carbides. Due to unexpected SF 6 dissociation, the synthesis process led to the preferential formation of iron fluoride compounds. Powder samples, submitted to calcining treatment (400°C, 3 h), showed an almost complete transformation to α- and γ-iron oxides retaining the nanostructure feature of the powder.