Now I am doing what I used to criticize with young students: I ask the experts instead of doing online research, but I would like to make use of the fact that probably many experts of graphenes are available on RG (which I am not). My first question is the following:
1. The Hummers method used to obtain graphene oxide uses very harsh conditions and dangerous chemicals. Is it not possible to use electrochemical method, such as anodic oxidation of graphite to obtain graphene oxide suspension? I assume that the electrode potential limit of water decomposition limits the available voltage - but is it not possible to use other solvents with higher stability?
My next question is:
2. What happens if we treat electrochemically graphite in the presence of e.g. organic amines in aqueous solution? Is it not possible to get nitrogen-doped graphene? In an analogous manner several other doped structures might be synthesized.
I know the answer for the first question, and yes it is possible to obtain graphene oxide electrochemically, you should check Robert Dryfe's publications he is doing some studies on the area https://www.research.manchester.ac.uk/portal/en/researchers/robert-dryfe(d7b9a726-94ea-41d0-994c-dc5d15c690ff)/publications.html
For the second question I don't have a answer, sorry.
First question: Yes it is possible, many different works present methods synthesis of graphene oxide by electrochemical exfoliation. It is very simple and low cost method, but not only GO suspension can be obtained, which was showed in my work. You must use X-ray diffraction method to determine structure of synthesized material.
http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8183294
You can also read publications showed in references in my work, in which different methods and influence of type of graphite electrodes were presented.
I do not think that the Hummers method can produce graphene (mono- or by-layer), but just crash micro-graphite into smaller particles where some are thin, 1~100 nm in thickness. The products are still definitely graphite comprising 3~300 graphene layers, whose crystallinity becomes poorer rather due to the harsh acid treatment.
Also, I understand that nobody have shown direct evidence of the presence of monolayer graphene in micron size. Please see the paper, Lee et al. Raman Radial Mode Revealed from Curved graphene, J. Phys. Chem. Lett, 8, 2597-2601 (2017), to know how to identify mono- or bi-layer graphene.
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