What does this peak in cyclic voltammogram mean? My sample is cellulose and it exhibits an oxidation peak and reduction peak. But what does this peak means aside from oxidation and reduction?? Why does it shaped like that? For example, a PANi has a peak in a cyclic voltammogram and those peak means transition from this state to this. Does my sample follow the same?
It is difficult to say unless you record the cyclic voltammogramm in your background solution (supporting electrolyte without cellulose). If you see the same pair of peaks as in your figure, it can mean also that your electrode is not clean enough and/or has the redox active species at the surface.
Hello Neil Madrigal ,
This peak, between 0.4 and 0.5 V vs. Ag/AgCl, appears to be a redox couple and you could also observe a shoulder just below 0.0 V vs Ag/AgCl. At the most negative potentials you appear to have the onset of oxygen reduction.
As Nataliya V Roznyatovskaya suggested, it would be useful to perform some CVs on your "blank".
Also could you provide more details of your setup. What is the pH of your system? Have you immobilised the cellulose on a glassy carbon electrode (GCE), planar gold electrode, etc.? How did you clean your electrode before use?
Best regards,
Marie B.
Thank you, Nataliya V Roznyatovskaya and Marie Berthuel !
This are the details:
Working electrode: Cellulose coated with carbon
Reference electrode: Ag/AgCl
Auxiliary electrode: Pt wire
Electrolyte: H2SO4
I know that it have an redox pair but I don't know why. Carbon should behave like rectangular CV but in my case it have peaks so it must be due to the cellulose but I don't know what part of cellulose is causing it. Do you have any kind of explanation for this?? or references?? I would really appreciate that. :)
Hello Neil Madrigal ,
Are you working with any redox probe at all? Before running this CV have you performed another experiment with any redox probe? Impurities might have get stuck in the frit of your RE or on your CE, I would suggest to check them just in case.
Otherwise I would suggest to clean your electrode before use. I generally perform an electrochemical polishing by running a CV from 0.5 V to -0.65 V (formation of H2 bubbles) to get rid off the impurities at the electrode surface.
Best regards,
Marie B.
Hi, Marie Berthuel !!
So the visible peak is due to the impurities in my working electrode??
Hello Neil Madrigal ,
The redox peak looks very reversible to come from cellulose. However, literature has shown than cellulose could display an electrochemical response.
These papers could interest you:
Article Direct Electrochemical Oxidation of Cellulose: A Cellulose‐B...
Article An electrochemical sensor based on cellulose nanocrystal for...
Best regards,
Marie B.
Hello Scientist, please hiw do i interpret my CV data? Which is the negative side Cathodic (reductive potential) and is the positive side anodic (oxidative potential)?
I look forward to hearing from you.
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