Non-Graphitizing Carbon: Its Structure and Formation from Organic Precursors

Non-graphitizing carbon, or char, has been intensively studied for decades, but there is still no agreement about its detailed atomic structure. The discovery of the fullerenes, and of related structures such as nanotubes, stimulated the present author and others to put forward models which incorporate non-hexagonal rings into hexagonally-bonded sp2 carbon networks, creating a microporous structure made up of highly curved fragments. However, this model has not been universally accepted. This paper reviews the models that have been put forward for non-graphitizing carbon and outlines the evidence for a fullerene-like structure. The influence of precursor chemistry on the final structure of the carbon is also discussed.