I would recommend AFM. TEM is also possible. Raman spectroscopy is useful for determining the number of layers in graphene but not graphene oxide. Similarly, xrd is useful for determining the number of layers in graphene but the peak obtained in the xrd pattern of GO may be too broad for practical use.

Please use atomic force microscopy and probe the thickness of the sheet. Based on monolayer thickness of GO, one can say how many number of layers are there in the GO sheet.

In addition to AFM you can also use Raman spectroscopy.The 2D band peak in the Raman spectrum of your graphene sample gives you some idea about the the number of layers of graphene.

All true...

Here is an example for your help.

http://onlinelibrary.wiley.com/doi/10.1002/smll.200901173/full

You can use the xrd technique. You can obtain the crystallite size and then with the interplanar distance you can calculate the number of layers.

Number of layers ≈ crystallite size / interplanar distance

what kind of graphene oxide you have, powders or film or dispersed in any solvent? if in film form, AFM would provide some information...if as dispersed or powder form, TEM would be the best choice to know the number of layers...

I would recommend AFM. TEM is also possible. Raman spectroscopy is useful for determining the number of layers in graphene but not graphene oxide. Similarly, xrd is useful for determining the number of layers in graphene but the peak obtained in the xrd pattern of GO may be too broad for practical use.

In Raman spectroscopy if Id/Ig

Yes, of course, you can determine the number of graphene/graphene oxide layers by following analysis:

1. Raman Spectroscopy (the ratio of D and G peaks intensities give the estimation of number of layers)

2. TEM (high-resolution image from edge of graphene film gives the estimation of number of layers)

3. AFM (thickness measurement from edge of graphene film gives the estimation of number of layers)

4. XRD (is workable for three and more than three layers of graphene/graphene oxide)

5. UV-Vis Spectroscopy (the transmission value gives the estimation of number of layers)

XRD is not as accurate as AFM or HR-TEM, but it is generally more accessible as an estimate. So, a good reference paper using XRD is:

Comparative study of different scalable routes to synthesize graphene oxide and reduced graphene oxide

A. Romero, M.P. Lavin-Lopez,, L. Sanchez-Silva, J.L. Valverde, A. Paton-Carrero

Materials Chemistry and Physics 203 (2018) 284-292

For those of you claiming Raman spectroscopy can provide information about the layer thickness of graphene oxide, can you please show us a paper on that? I'm interested on this question.