Non-catalytic CVD preparation of carbon spheres with a specific size

A simple chemical vapor deposition method was used to prepare carbon spheres (CPS) from toluene without any catalysts. The diameters of CPS are in a range of 60 nm to 1 mum and can be controlled by changing the composition and flow rate of a mixture gas that was used as the carrier gas. The carbon spheres have been systematically studied by scanning electron microscopy (SEM), element analysis, energy dispersive X-rays spectroscopy (EDX), X-ray diffraction (XRD) and ultra-violet laser Raman spectroscopy. The SEM examination shows that these carbon spheres have a ball-like and chain-like morphology, all of which have smooth surfaces and a quite uniform diameter. The element analysis reveals that the carbon content of the spheres is over 97.0% while the EDX analysis shows that more than 92.0% of the carbon spheres is carbon. The XRD and UV-Raman studies reveal that they are not highly graphitized carbons. (C) 2004 Published by Elsevier Ltd.