Carbon nanostructure reactivity: Reactions of graphite powders with ozone

Abstract

The kinetics of ozone absorption by fine graphite powders at 20 degrees C, the behavior of unpaired electrons of the graphene conjugated systems, and IR spectra of surface functional groups were studied. It was shown that ozone reacts with six-membered cycles at the graphite surface. After one-sixth of the accessible surface six-membered cycles were consumed, the reaction slows down sharply, probably due to the inductive influence of the functional groups formed, the reaction leads to a significant loss of the sample's mass. The observed changes of the ESP spectra in the ozonation process are indicative of free radicals localization at the surface layers, increase radical concentration and its transformation to peroxide radicals. The reaction of ozone with a graphite surface is accompanied by formation of local zones of destruction, which decrease the reactivity of the neighboring areas to ozone and thereby protect the remaining graphite surface nanostructures from further decomposition. The similarities and differences between graphite and fullerene C-60 nanostructural units in reactions with ozone were considered.