Carbon redistribution processes in nanocarbons

Here we present the results on carbon atom redistribution processes in the closed systems leading to etching of the carbon nanostructures with a high surface energy and to simultaneous formation of bulk graphitic structures. The TEM study of the products produced by treatment of nanodiamond and their annealing products in closed vessels at 2140 K and controlled pressure of CO, CO(2), and H(2)O gases shows formation of the low surface area graphitic ribbon structures and polygonized graphitic particles. We have proposed that in a closed system carbon atoms redistribute due to the reversible reactions of carbon and different hydrogen- and oxygen-containing gases. Thus, these reactions are considered as carbon transport reactions. Intermediates of the growing structures were characterized with high resolution TEM. The basal plane edges and arched basal planes formed on the graphite crystal edges are suggested to be growing centers. (C) 2004 Elsevier Ltd. All rights reserved.