The type of disorder can be qualitatively analyzed using the intensity ratio between the D and D' bands, ID/ID'. The ID/ID' of NPGs is ca. 5. This indicates that these NPGs have both vacancies and grain boundaries since the ID/ID' values lie between those of graphene dominantly with vacancies (~7) and grain boundaries (~3.5). The shoulder peak at ~1150 cm -1 in the Raman spectra proves the existence of Stone-Wales (SW) defects, while the small peak at ~2460 cm -1 can be attributed to the SW+D band.