I have carried out XPS analysis of Ag based nanocomposite. XRD and TEM analysis confirms the presence of Ag. But it is not showing any peak related to Ag in XPS data. What might be the reason?
There are several possible reasons why you are not observing any peak related to Ag in your XPS data despite confirming its presence using XRD and TEM analysis. Some of these reasons include:
It is important to carefully consider these factors and optimize your XPS analysis conditions to ensure the accurate detection of Ag in your nanocomposite sample.
It is difficult to say much without seeing spectra or knowing more about your samples. Clearly your materials are crystalline with particles bigger than 5nm or so as you get an XRD reflection for Ag so may well expect to see in XPS.
Therefore point to think about are:
1. What is the size and dispersion of the Ag - large (e.g. micro sized) particles and a poor dispersion mean the Ag could be "invisible" to XPS, whereas many smaller particles wouldn't be.
2. You have significant carbon contamination hence attenuating the Ag 3d signal (which may be weak depending on particle size as in point 1)
3. The Ag is in the bulk of the material and not the surface (i.e. not distributed well in roughly top 10 nm of material)
4. I really wouldn't worry about points 2 - 4 in the answer from Febin, if Ag is there and in detectable quantities, the XPS will detect it regardless of oxidation state or any reduction
I asked Bing's new AI feature this question and got an answer remarkably similar to one of the ones already posted. Very depressing.
There are several possible reasons why you are not observing any peak related to Ag in your XPS data despite confirming its presence using XRD and TEM analysis. Some of these reasons include:
- Detection limit: The amount of Ag present in your sample may be below the detection limit of your XPS instrument.
- Surface sensitivity: XPS is a surface-sensitive technique and may not detect Ag atoms that are buried beneath the surface of your sample.
- Chemical state: Ag may be present in a chemical state that is not detectable using XPS. For example, Ag may be present in the form of an oxide or alloy that does not produce a distinct Ag peak in the XPS data¹.
I hope this helps!
Source: Conversation with Bing, 4/3/2023(1) Why XPS do not show peak corresponding Ag even though the XRD shows the .... https://www.researchgate.net/post/Why_XPS_do_not_show_peak_corresponding_Ag_even_though_the_XRD_shows_the_corresponding_peaks Accessed 4/3/2023.
(2) Is it possible to find peak only in XPS , not XRD? | ResearchGate. https://www.researchgate.net/post/Is_it_possible_to_find_peak_only_in_XPS_not_XRD Accessed 4/3/2023.
(3) Practical guide for curve fitting in x-ray photoelectron spectroscopy. https://avs.scitation.org/doi/10.1116/6.0000377 Accessed 4/3/2023.
(4) Characterization techniques for nanoparticles: comparison and .... https://pubs.rsc.org/en/content/articlehtml/2018/nr/c8nr02278j Accessed 4/3/2023.
To get a sustainable solution to your problem, please refer to the preprint article given at link DOI: 10.13140/RG.2.2.27720.65287/3 or at link https://www.researchgate.net/publication/352830671.
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