Reduction of graphene oxide by electron beam generated plasmas produced in methane/argon mixtures

Graphene oxide (GO) was controllably reduced using electron beam generated plasmas produced in methane/argon mixtures. Operating parameters including, total pressure, duty factor (the ratio of the pulse duration to the pulse period), treatment time, and methane flow rate were varied to determine their impact on the reduction process. The resulting surface chemistry, topography and crystallinity of the reduced graphene oxide (r-GO) was determined with X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy. Oxygen concentration could be tuned to values between 43 at.% and 5 at.%, and under certain operating conditions the sp2 cluster size grows. System diagnostics identified the critical operating parameters for the reduction of oxygen in GO.