Graphitization of activated carbon under high pressures and high temperatures

Activated carbon was treated at 5.0 GPa up to 1600 degrees C and the structural evolution in the graphitization process was investigated. The graphitization temperature is reduced to 1200 degrees C at 5 GPa, as reflected by x-ray diffraction patterns. Honeycomb-like structures come into being in the high-pressure sintering temperature range of 1000-1100 degrees C and slice-like structures appear after graphitization. Raman frequency and half width drop drastically near the graphitization temperature, and the appearance of D and D' lines indicates there are still some disorder structures in the graphitized activated carbon. (C) 2009 Published by Elsevier Ltd