An analysis of the molecular structure of graphite by estimating the small number of edge sites

Abstract

Graphites have been widely used as electrode materials, heat resistant materials and the like, because they have high chemical stability and electrical conductivity. These superior properties can be ascribed to their highly developed and crystalline carbon structures, which can be analyzed by X-ray diffraction and transmission electron microscopy. These techniques have been regarded as primary identification tools for the crystallographic understanding of a carbon structure, but do not provide any direct information about the chemical characteristics of graphites which greatly depend on the number and quality of edge planes. The quantitative analysis of the edge planes is thus indispensable for the full understanding of carbon reactivity. However, it is not an easy task for graphites, because the total number of edge sites in these carbons is too small to be detected with high accuracy. In this paper, we introduce techniques for analyzing a small numbers of edge sites in graphites and for drawing a true picture of the carbon structure in them by estimating the average size of graphene sheets from the total numbers of carbon edge sites.