Synthesis and characterization of carbon nanostructures by evaporating pure graphite and carbon black in detonation-gas arc discharge

• Arc discharge experiments have been carried out in detonation gas.
• The competitive growth of graphene nanosheets and particles is shown.
• High-crystalline graphene oxide has been prepared and characterized.
• Raman spectra of as-deposited carbon nanostructures show different fingerprints.
• Materials and atmosphere pressures jointly lead to the varying formation mechanisms.

Arc discharge experiments combined with explosive detonation have been carried out to probe the transformation of pure graphite and carbon black evaporated in detonation gas. Under respective conditions, different kinds of carbon nanostructures have been synthesized including few-layer graphene (FLG) nanosheets, polyhedral graphite particles (PGPs), carbonaceous monocrystals and graphene oxide (GO). The evaporation of graphite facilitates the formation of FLG and PGPs, which exhibits competitive growth according to the pressure of detonation gas. By evaporating carbon black, a considerable amount of high-crystalline GO with low oxygen concentration are acquired. The morphology, crystal structures, Raman spectroscopic fingerprints and chemical compositions of these products are investigated by the characterizations of transmission electron microscopy (TEM), high-resolution TEM, Raman spectra and X-ray photoelectron spectroscopy. The formation mechanisms of such carbon nanostructures in arc evaporation are discussed according to the chemical nature and pressure of detonation gas.