Dear Muhammad,

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Jeffrey is right;

we have to know a little bit more details about your experiment 

(for example on how you modify your sample and how were the conditions around).

Thanks in advance

What are the physical conditions of the samples? Are they powders or films? How are they mounted on the sample holder? What are you doing during sample analysis to handle charge neutralization in each case? Do you use an electron flood gun?

The observed binding energies will depend on the specific environment where the functional group are located.

See typical C 1s  binding energy

Amine                                       C-N                   286 eV

 …………………………………………………………

2F bound to carbon             – CH2CF2              290,6 eV

Best regards.

Mr. Yuri Mirgorod, Bundle of thanks. I have modified g-C3N4 with MOF of Cu and it also has Cl in it. It means due to new interactions between g-C3N4 and MOF of Cu. The peak positions have been shifted towards high binding energy.

In addition to all points above I would also add the binding energy referencing - how did you correct for charging?

G. Greczynski, Could you please elaborate it further? about binding energy referencing

Do you have similar shifts in N 1s spectra? If the shifts follow same trend (direction) and are close in values, a charge compensation/BE scale referencing issues (as Grzegorz Greczynski pointed out) might be a reason. It would be also good to know C/N atomic ratios and other elements, oxygen in particular, present.

And there seems to be Cl in some of the samples, a quite electronegative element such as oxygen and fluorine, thus binding energy shifts may be expected.

Andrey Shchukarev, Yes Sir, similar trends in shifts in N 1s and O 1s spectra are also present. They are closely related. Sir other elements are Cu, Cl and Oxygen

Dear Mohammad, Similar BE shift  (in the same direction!) of photoelectron lines for all main elements, C1s, N1s, and O 1s,  indicates that observed effect is not a chemical shift, but surface charging/BE scale calibration issue. It most probably originates due to change in sample conductivity caused by treatment. Hope it helps. Best regards, Andrey

Thank you very much Sir ffor your valuable time and guidanc.