Preparation of carbon sphere from corn starch by a simple method

Carbon spheres with a regular and perfect shape was successfully synthesized from corn starch by a two stage process: oxidation and carbonization. In this process, oxidation treatment was the main step; the optimal oxidation temperature was 210 degrees C. The resulting products were characterized by using combined techniques including X-ray powder diffractometer (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The results showed that the products could keep the original shape of corn starch perfectly, and the diameters of carbon spheres ranged from 5 to 25 pm. It showed characteristic structure of non-graphitizing carbons heated at high temperatures. The preparation mechanism has also been discussed. (C) 2008 Elsevier B.V. All rights reserved.