Graphene plane

Compared to PAN and pitch-based carbon fiber, the morphology of VGCF is unique in that the graphene planes are more preferentially oriented around the axis... 

When the electrolyte solutions are not too reactive, as in the case of ethereal solutions, there is no massive formation of protective surface films at potentials above Li intercalation potential, and most of the solvent reduction processes may occur at potentials lower than 0.3 V vs. Li/Li+. Hence, the passivation of the electrodes is not sufficient to prevent cointercalation of solvent molecules. This leads to an exfoliation of the graphite particles into amorphous dust (expholiated graphene planes). This scenario is demonstrated in Figure 2a as the reduction of the 002 diffraction peak21 of the graphite electrode, polarized cathodically in an ethereal solution. 

Fig. 3 Proposed representation of an M-N2 active site with pyridinic nitrogen species on the edge of the graphene plane, reproduced from ref. 139.

Fig. 4.8 Structure of graphite, pointing to 3D hexagonal unit and covalent bonds between carbon atoms, and van der Walls bonds between graphene planes and hydrogen...

More conventional process to prepare active carbons is by chemical activation. So-called activated carbons consist of multitude of stacks of graphene planes of various sizes and degree of disorder. Such carbons are highly macro- and mesopo-rous materials. 

Fig.1 Positional relationship between two identical graphene planes. Graphite structiu e can be described as an alternate succession of these basal planes. The right panel was taken from the image gallery of Prof. R. Smalley (to be foimd at http //smalley.rice.edu/ and reprinted with his kind permission...

Materials should be characterized and described in as many details as possible, because the nanotube toxicity can depend on by-products of their synthesis as well as on their design. It would be desirable to provide at least information on their composition (including metals and heteroatoms, which are present in a quantity higher than 0.1%), detailed description of morphology, data on surface chemistry, crystallinity, and spatial organization of graphene planes ... 

---