Very unlikely, unless combined with very strong reductive environment.

Simple X-ray beam do not reduce graphene oxide during XPS measurements.

Very unlikely. 

Hi Srikanth, have you ever recorded any change in XPS spectra after XPS measurements?

Hi Adam, Khaled and Nirupama, any possibility about the excited-photoelectrons induced reduction?

Never saw it on GO samples. We did it on many samples by using old type double anode source and monochromatic Al source focused to 200 - 500 micrometers. The samples never have bee reduced.

Thank you everybody for the valuable inputs. The reason for this question was I have been observing a change in the XPS spectra of "monolayer GO" wherein the 284.8 keeps getting sharper and I have seen a decrease in the intensity of the C=O, C-O-C and the COO peaks. Spectra was taken after every 60mins and at the same spot.