I have deposited Graphene oxide on Cu substrate with the help of electrochemical work station with the negative voltage applied. I got 3 peaks at different range. What does these peaks means at different range?
Graphene usually appears at 2 theta = 26.5 o, but in your case, you are depositing graphene oxide by electrochemically, hence, there is a chance of reduction of GO.
The peak position of graphene oxide varies from 10 to 18º, depending on the preparation method, the number of graphene layers, defectiveness degree, etc., I think
See, for example, Shangkun Li, Xiaofeng Lu*, Yanpeng Xue, Junyu Lei, Tian Zheng, Ce Wang Fabrication of Polypyrrole/Graphene Oxide Composite Nanosheets and Their Applications for Cr(VI) Removal in Aqueous Solution // PLOS ONE, 2012, V.7, Issue 8, e43328