Chemical reactions between calcium carbide and chlorohydrocarbon used for the synthesis of carbon spheres containing well-ordered graphite

Carbon spheres and carbon nanospheres were prepared through the chemical reactions between calcium carbide and chlorohydrocarbon without using any catalysts. The reactants were sealed in a pressure vessel and heated to temperatures of 210-250 degrees C. The final products were characterized using scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS) attached to SEM, transmission electron microscopy (TEM), Xray diffraction and Raman spectroscopy. SEM and TEM examinations show that some of the obtained products are bead-like or roe-like spheres with diameters of 100-2000 nm. The carbon nanospheres have high purity (>95%) and uniform size distribution (100-200 nm). The EDS analyses reveal that the carbon contents of the spheres are 86-94%. The results indicate that the size and the size distribution of the synthesized spheres change with the change of the reactants. The experimental yields of carbonaceous materials relative to the starting materials are about 8.0-14.4% (w/w). The yields of the spheres increase whereas their size distributions decrease with the increase of H atom and the decrease of Cl atom in chlorohydrocarbon. The average graphitization degree of sample 1 and sample 2 are 81.9% and 78.7%. (C) 2010 Elsevier Ltd. All rights reserved.