Can anyone refer to articles on setup for the two compartment cell CV? I have seen "working compartment with working electrode and reference electrode" and second compartment with counter electrode. Another set up refers to first compartment with working and counter electrodes and the second compartment with reference electrode. Which one is it? Is the setup for CV and bulk electrolysis the same?
It depends on your task: if you want to prevent diffusion of the species formed on the counter electrode towards the working electrode, so the right set-up is the first one ( working compartment with WE and in close proximity RE, another compartment is with CE). If your RE doesn't have a salt bridge (the most of commercial RE already have it), you can separate your RE from working compartment, where you have WE and CE. Bulk electrolysis is often carried out galvanostatically and in two-electrode system, i.e. without RE. So the set-up for CV and electrolysis is not always the same.
Hello Nataliya, I am using Ag/AgCl reference electrode. Therefore, the working compartment should have working and counter electrode (GC electrode and Pt mesh)?
Asmita: As Nataliya wrote, it all depends on your task. If you need to protect your reference electrode from anions or other foreign species in your working electrolyte, you can use the second compartment to isolate the reference electrode. If products of the counter electrode reaction can interfere with processes at the working electrode, then you probably need to move the counter electrode to the second compartment. In a 3-compartment cell, you would place the working electrode in the center and the other electrodes in separate compartments. Options for protecting the reference electrode in the working compartment include use of a Luggin capillary or a gelled salt bridge. In the latter case, you definitely need to be cognizant of junction potentials, as also with separate compartments unless both are swamped with the same supporting electrolyte.
I am working on water oxidation. I have working electrode and counter electrode in one compartment with 0.1M electrolyte and 1mM catalyst. To prevent leaching of chloride ions, I have Ag/AgCl electrode in the second compartment.
I agree with Nataliya V Roznyatovskaya . It is customary to have the working electrode and the reference electrode in close proximity ( i.e in the same compartment). To isolate the products of reaction , the counter electrode is located in the second compartment. The commercial reference electrodes do have a glass frit that isolates the offending anions. The main point is to locate the reference electrode very close to the working electrode either directly or through a Luggin capillary.
Asmita,
If you you use a commercial Ag/AgCl which has a glas frit, but the leaching of chloride still interfere your measurement or you still try to minimize it, you can use a second salt bridge and fill it with your electrolyte, i.e. separate your RE with two salt bridges . However, as far as you use relatively dilute (0.1M) electrolyte, I would prefer a construction called Luggin capillary, as Peter Adcock and Srinivasan Venkatesan have already mentioned it.
In order to minimize impurities, use a H2 charged Pd electrode as the reference electrode. Then, use a Pt-disk and measure the RHE potential in situe. The RHE-potential is the preferred reference potential to which you want to express your data given that you are working with water oxidation.
Further, do not forget to compensate for the solution resistance...
I agree with Gustav. If you do not have a means to make a standard hydrogen electrode, you can buy one from a company called GASKATEL in Germany. they use a metal hydride to supply the hydrogen.
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