We are to conduct UV vis of Cr doped ZnO but we are stuck in making solution... di water doesn't work... can we use HCl as a solvent for such transition metal doped metal oxides.. how about ethanol...? And in what quantity should the powder and solvent be...?
Please look at the following below links which may help you in your analysis:
http://www.scielo.br/pdf/ce/v60n355/15.pdf
https://www.ias.ac.in/article/fulltext/boms/038/05/1359-1365
Thanks
Do you mean, you want to disperse the powders in a solution before taking a UV-Vis spectrum? If it's to disperse your powders, ideally an organic solvent like ethanol should work just fine. The quantity of powder would depend on its dispersibility and for a ZnO based host, you shouldn't have a problem with that and hence a few (2 - 3) mg in a cuvette should be okay. Make sure you take the background as EtOH.
However, ideally, the best way to measure UV-Vis of powders is to do so in the solid form without dispersion using an integrating sphere. It's a more accurate method of determining the bandgap of a material (unless your objective is not the bandgap and is something else!)
But, if it's something else you want to measure, please specify so and I'll be happy to help
Either disperse the nanopowder in a suitable solvent like ethanol or obtain a thin film of the material and then test for its absorption characteristics.
Dear Pirzada,
Take 2-3 mg of Cr doped ZnO in 3-4 ml ethanol or hexane and then sonicate the solution for 15-20 minutes to disperse the Cr doped ZnO in ethanol or hexane. Now perform the UV-Vis spectra of Cr doped ZnO using the corresponding solvent as a background and try to maintain the maximum absorption value
Samvit G. Menon Thank you sir.
My aim is to find bandgap of the sample. Our UV-Vis device is set to give the graph with respect to wavelength; Transmission or Absorption vs wavelength.
the cuvette capacity to contain solution up to 10 ml.
Shrikaant Kulkarni sir where do i deposit the thin film for the purpose of UV-vis? will glass slide do? is it necessary that the thin film be transparent? or it is okay if it is translucent or opaque...???
Rathindranath Biswas dear our cuvette can contain 10 ml of solution. in order to make solution we had used 20 ml of ethanol for just around 3 mg of the powder... that didn't work as well... can't understand where is the fault... but now sir Shrikaant Kulkarni has suggested to make thin film of the solution....
Deposit the wafer thin film on glass slide and place the slide in cuvette and allow the light to pass through it. The film should be transparent.
First why don't you use only powder like one of the senior have mentioned in above answers. Second you can make film on glass, FTO, and ITO but anything you use you have to use same as reference. So for film making you can use doctor blade, drop casting AR electrodeposition method.
Jafar Hussain Shah sir the sample is in powdered form. Now to deposit thin film on glass substrate we make solution of powder in ethanol and try to dissolve it. Then we use a transfer pipette to for deposition on glass while the glass is on hot plate.... Is This Method correct?
Yes that is enough but just for better result try to get uniform film. so what kind of problem after it you faced? Zain Pirzada
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