Fe-inserted and shell-shaped carbon nanoparticles by cluster-mediated laser pyrolysis

We report here the high-yield continuous synthesis of carbon nanoparticles with and without Fe content by laser pyrolysis technique. The laser beam decomposes (via C2H4 sensitizer) the Fe(CO)5 as Fe clusters which absorb themselves the laser radiation. They trigger the fast carbon particles formation by exothermic dehydrogenation/polymerization of the surrounded C2H2 molecules. This combination between Fe clusters and C2H2 generates nanoparticles with unusual structure. Depending on the gas pressure in the reaction chamber, two kinds of nanoparticles were obtained: at lower pressure, 30–40 nm diameter particles with a defective structure, part of them crowded with Fe clusters (3–6 nm) and two types of nanoparticles (around 50–60 nm) at the highest pressure. Some of them have a shell-shape structure, presenting a distinct envelope, other with a turbostratic arrangement, and few containing one or several smaller (3–20 nm) Fe nanoparticles trapped inside. We consider that these particular structures of our nanoparticles may be useful in applications such as MRI applications, drug delivery or catalysts.