The ISO definition:

Single layer Graphene: single carbon atom；

       The physical properties of graphene are very sensitive to the number of stacked layers.With fewer layers, the larger the crystal size, the closer the stack is to a single layer of graphene.Therefore, the number of stacked layers is a key factor in the definition of graphene.

       GO (Graphene oxide) has a large number of functional groups on the surface of Graphene oxide
RGO (Reduced Graphene Oxide) The GO was reduced with a reductant, and the surface was defective, with a small number of functional groups depending on the reduction degree.

      GP(Graphene) It generally refers to the Graphene without defects and functional groups on the surface, which can be obtained by graphite peeling or gas-phase deposition.

      Compared with graphene, the lattice symmetry of graphene oxide GO and rGO during the synthesis process are damaged and the vibration frequency of carbon atoms is affected, which causes great damage to its structure and its performance cannot well be shown.

      The difference between graphene and r-GO is about the same as between iron (Fe) and rust (Fe2O3) which also contains some 25% of oxygen.