Carbon spheres

The discovery of fullerenes has opened up new studies in shaped carbon materials. In particular the discovery that carbon atoms in fullerenes showed curved sp2 bonding also led to the discovery of single walled carbon nanotubes and a re-investigation of carbon fibers and tubes. The area of shaped carbon materials has since been dominated by studies of carbon nanotubes. The discovery has, however, also impacted on the well known spherical carbons exemplified by carbon blacks. Over the last two decades this has led to a resurgence of interest in solid carbon spheres as well as core–shell spheres and hollow carbon spheres. In this review, developments in the synthesis, doping and functionalization of spherical carbon materials (but not fullerenes) are highlighted. The chemical and physical properties as well as the uses of the spheres are also described.