  Based on density functional calculations, we demonstrate a significant
difference in oxidation patterns between graphene and graphite and the
formation of defects after oxidation. Step-by-step modeling demonstrates that
oxidation of 80% of the graphite surface is favorable. Oxidation above half of
the graphite surface significantly decreases the energy costs of vacancy
formation with CO2 production. The presence of water is crucial in the
transformation of epoxy groups to hydroxyl, the intercalation with further
bundle and exfoliation. In water-rich conditions, water intercalates graphite
at the initial stages of oxidation and oxidation, which is similar to the
oxidation process of free-standing graphene; in contrast, in water-free
conditions, large molecules intercalate graphite only after oxidation occurs on
more than half of the surface.
