Hello. I am running cyclic voltammetry with bare gold electrode. The voltammograms are very different from that in literature. Please see attached file for the image. What could be done? Thank you.
There are a lot of possible reasons to get poor/wrong CV. Without more information there is no way to know what is happening here, but my guess would be that settings/setup are not proper.
Additional information that would be useful: what is your electrode size, what is your electrolyte, is this a standard 3-electrode cell, and if so what reference electrode are you using, are all your leads connected (at least 3 but up to 5), what are your exact settings (votage range, scan rate, sample period/type...), is the system set to autorange or do any iR compensation...?
It's a standard three-electrode cell using SCE as reference electrode ang weak sulfuric acid as electrolyte. Attached files are images of the electrodes and plot taken at current range 1000 uA, voltage range -0.3V-1.6V, scan rate 50 mVs-1 ..
I'm not 100% sure what I'm looking at with those electrodes, but they look like 2-electrode SPEs (or some other patterned electrode type), not 3. Are you using a standard reference electrode in addition to these? As for the data looking at that plot it looks a lot like there's a short between the working and counter and the current is going to the range limit over most of the scan. (There's also some noise, but the source for that is harder to address.)
Thank you, Jacob. Yes, I'm using SCE as RE in addition to the 2. How can I increase the current if the limit in my instrument is only 1000 uA? Is there a way to control the current?
re-check the solution you made and plug the three electrodes.as I see in the image, you have a problem with the electrical connection.
From your CV's the current range is obviously limited, try running your exp. at say 5mv /sec this should reduce current density somewhat. Use some good quality epoxy to reduce the size of your gold electrode. Increase the size of the counter electrode, check all connections etc... At 100mv/sec if I remember correctly peak currents are several hunderds of mAmps/cm^2 in 1M H2SO4 and are further related to the crystal plane . Also take care not to contaminate the solution with halogen salts.
Best regards, Mike
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