A Novel Chemical Synthesis >1 μm2 Reduced Graphene Oxide Sheets

If graphene is to be incorporated into transistors, solar cells, and capacitors, a large-scale synthesis of graphene must be devised. This research developed an innovative, simple, and cost-efficient synthesis procedure, dispersing graphene oxide in an ethanol-water solvent and reducing slowly with sodium borohydride (NaBH4). Reducing graphene oxide in 75:25 and 50:50 H2O:ethanol solutions with 15 mmolar NaBH4 produced numerous single-layered reduced graphene oxide sheets >1 µm2, and sometimes even >2 µm2. The quality of these sheets was confirmed by Raman spectroscopy, XRD, TGA, TEM, ED, and HRTEM.