Tuning the defect density in chemically synthesized graphene

Gram-scale quantities of graphene sheets can be synthesized in a bottom-up chemical approach and we have sought to address the extent of the defect density using various characterization techniques which include X-ray diffraction, high resolution transmission electron microscopy, single area electron diffraction, Raman spectroscopy, atomic force microscopy and X-ray photoelectron spectroscopy. It was found that the chemically synthesized graphene sheets have a tendency to stack without inter-planar coherence such as that found in graphite. The driving force behind this stacking is believed to be due to ¿-¿ interactions between overlaid carbon sheets. The overall defect density was shown to decrease by simply varying the carbon precursor used in the chemical synthesis.