Morphology and surface structure of nanocarbon allotropes: a comparative study

Abstract

Different carbon allotropes, including vulcan carbon, multiwall carbon nanotubes, graphene, and nanodiamonds, were processed by chemical purification and treated in a mixture of H2SO4–HNO3. The materials were characterized by infrared and Raman spectroscopy as well as by scanning and transmission electron microscopy. Oxidative differences are indicated by Raman through the G band (∼1570 cm−1), D band (∼1340 cm−1), and G’ band (∼2684 cm−1). The crystal size (La) and purity, relative to the amorphous carbonaceous material, were studied as well, along with the morphological changes induced by the treatments