Catalytic chemical vapour deposition synthesis of carbon spheres

Carbon spheres (CSs) were successfully grown in the presence of cobalt-silicon-mesoporous aluminum silicate (Co-Si-MAS) by chemical vapour deposition (CVD) using C2H2 as the source of carbon at 850 degrees C. The Co-Si-MAS catalysts with Si/Al molar ratios of 25, 50, 100 and 150 were synthesized by sol-gel preparation and followed by anchoring process. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) images and Raman spectroscopy experiments showed that the obtained CSs possess nearly perfect spheres with diameters range from 650 to 1000 nm. It was found that CSs were fabricated under a thin film that was deposited during the catalytic reaction. On the basis of qualitative analysis it was revealed that the film included cobalt, silicon and aluminum elements. This thin film was applied as a catalyst for the synthesis of CSs. (C) 2009 Elsevier B.V. All rights reserved.