Please have a look at the image. I am unable to interpret and reason the peak shift towards left. Moreover the 2nd peak at around 30 is of silver oxide ?
the peak is supposed to be of Silver nano particles that have been synthesized from algae.
Need your valuable comments.
I beleived that it is the XRD diffractogram !!!
What is your sample? Are you sure that it is silver ? metallic? oxide?
The nano particles have been synthesized from algal extracts. i am expecting metallic silver nano particles.
I mean, what are we looking at, obviously the axis are labeled intensity and 2*theta, so it is a pXRD pattern. But what is the compound that is being analyzed? Is it supposed to be bulk metallic silver, silver nanoparticles, silver oxide? I mean, to be honest, it doesn't really look like any silver I've encountered before (but that does not mean that it is not a silver compound).
i have prepared silver nanoparticles from algal extracts. After UV-vis analysis of the dispersion silver peak was indicated and the size was further confirmed by SEM. the dispersion for XRD was lyophilized prior to perform the XRD. so i am expecting the nanosilver crystals. There ofcousre exists the possibility of the oxidation of silver atoms (Metallic Silver) into its oxide..
i am unable to interpret what has gone wrong. and i need help. the Peak is close to that of metallic Silver but is not at the exact position which is confusing to me
@Atilla yes the compound is Silver .. as indicated from XRF and EDX analysis. i am expecting metallic silver. but it may be oxide. this is where i am stuck , weather it is metallic silver nanoparticles of Silver Oxide.
A similar question has been asked previously about something like this:
https://www.researchgate.net/post/In_XRD_of_silver_nanoparticles_what_does_the_2theta_value_at_32_degree_mean_How_to_interpret_it
You may want to take some of your sample and use TEM and EDX (not perfect) but may help resolve what could be causing your issue. Given that you using an alga extract I have a feeling that your Ag-NPs are being coated with something in the preparation step that is making you Ag-NPs have more irregular crystal structures. Also are you sure that you are looking at true nano-Ag? Depending on your prep, media, and so on, AgNPs can be very unstable (especially uncoated/non-functionalized).
You may want to TGA some of you sample.
Good luck.
two theta doesn't mean much unless you give the x-ray energy. Better to convert it to d-spacing to try to identify what kind of unit cell could have such a d-spacing.
Dear Uzair,
this XRD has definitely something wrong. From the online free database (http://rruff.geo.arizona.edu/AMS/amcsd.php), it's a little bit outdated but it works for simple elements, I found the following:
-AgO has a 100% intensity peak at 32 2theta
-Ag2O has a 100% intensity peak at 33 2theta
-Ag has a 100% intensity peak at 38 2theta
so far NONE of these peaks belong to your diffractogram OR they are wildly shifted. Besides, you never have the enlargement typical of nanomaterials.
My guess would be:
-you are looking at the sample holder alloy
-you are wildly out of focus during measurement (generally the height of the sample) so your peaks shift a lot
-you did not measure enough powder (so you basically see only the sample holder)
By the way, what Lawrence suggests might be a good solution to solve the problem.
Think about it.
Dear Uzair,
Do you know this recent paper
International Journal of Metals
Volume 2014 (2014), Article ID 692643, 8 pages
http://dx.doi.org/10.1155/2014/692643
Algae Mediated Green Fabrication of Silver Nanoparticles and Examination of Its Antifungal Activity against Clinical Pathogens
Shanmugam Rajeshkumar, Chelladurai Malarkodi, Kanniah Paulkumar, Mahendran Vanaja, Gnanadas Gnanajobitha, and Gurusamy Annadurai
Environmental Nanotechnology Division, Sri Paramakalyani Centre for Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, Tamilnadu 627412, India
The authors check for the possble presence of AgNO3 that can be involved during the synthesis method.
No only the used XRD, but also FTIR, UV, SEM, TEM, pH etc analyses..
Can you process similar investigations?
Best regards
Daniel
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