A Quantitative Analysis of Trace Amounts of Hydrogen and Surface Oxygen Complexes for Graphites and High-temperature Treated Carbons in Relation to Their Molecular Structures

摘要

Surface chemistry of carbon materials, especially the amount and nature of surface oxygen complexes at edge planes, is an important factor affecting their chemical characteristics. A number of researches have therefore made great effort to analyze surface oxygen complexes with various means so far. However, such analysis is not an easy task for graphite and high-temperature treated carbons, because, in these carbons, the total amount of surface oxygen complexes is too small to be detected. There have been some studies on graphite, but none of them have tried to quantitatively analyze the amount of surface oxygen complexes. In this work, we try to develop a technique to quantitative analyze the amount and the nature of carbon edge sites which are either terminated with hydrogen atoms or present as a surface oxygen complex in graphite and coke carbons heat-treated over 2400 oC. Besides, we also attempt to reveal their actual carbon structure from the average size of carbon layers calculated from the total numbers of carbon edge sites by using a method similar to the indirect one proposed by Aso et al. in order to understand their carbon structures.