Investigating the graphitization mechanism of SiO(2) nanoparticles in chemical vapor deposition.

The use of SiO(2) as a catalyst for graphitic nanostructures, such as carbon nanotubes and graphene, is a new and rapidly developing catalyst system. A key question is whether carbide phases form in the reaction. We show the formation of SiC from SiO(2) nanoparticles for the synthesis of graphitic carbon nanostructures via chemical vapor deposition (CVD) at 900 degrees C. Our findings point to the carbothermal reduction of SiO(2) in the CVD reaction. The inclusion of triethyl borate apparently accelerates the process and leads to improved yields. The study helps better understand the growth mechanisms at play in carbon nanotube and carbon nanofiber formation when using SiO(2) catalysts.