Cyclic voltametry is a qualitative technique but what if electrodeposition takes place during CV cycles? How to quantify the amount of deposit from CV profile?
What is the guarantee that the quantity of deposit obtained from area under cathodic curve is exact?
If the cathodic peak correspond to the well-defined reduction process that ends-up with the deposit on the surface and if you know which process is that (number of electrons), than I guess that you should be able to use that CV to calculate the amount of that electrodeposited material.
I guess that the answer depends on how you define the exact? Which other method can give you a 100% valid value.
In addition to Aleksandar comments,
I order to obtain the amount deposited, you have to obtain the charge under the curve of the deposition peak but you have to subtract the background current, that is, the current measured during these voltages during the CV only with the support electrolyte.
First you need to obtain the charge Q (area under the curve in the CV/scan rate). As Jordi said, you have to substract the background current, but there are software that do it automatically. Then you use the 1° Faraday law and you can obtain the mass deposit:
m =𝑄𝑀/𝐹𝑛
Or you can obtain the active area of the electrode with randles-sevcik, and then obtain the surface coverage (Γ):
Γ=Q/nFA
Thanks velentina.
Can you please suggest me one of the software to substract the background?
Dear Velentina
Can you please you please forward the steps? I'm also using the CHInstruments potentiostat.
Thanks
You are absolutely right John. We did the CV just to find out the deposition potential and after CV, deposit was observed on the working electrode and we don't know the quantity of deposit hence the question.
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