Episode 12: Season Finale!
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- Опубликовано: 9 сен 2024
- Episode 12: Season Finale! It's been a fun ride doing the electrochemistry podcast. We finish off this first season of the podcast off with a bit of a rant between Neil and Alex about all the topics we've struggled with in electrochemistry. Hopefully, you will enjoy and relate to this little venting session between Neil and Alex.
Great podcast. I enjoyed every episode. Thank you, Pine Research!
Glad you enjoyed it!
I need to discuss about Cyclic voltammetry results of my research..
(1) how to know from the area under the curve of CV curve whether the reaction is reversible or not?
(2) my CV curve has two oxidation peaks and one reduction peak...what is the reason behind it? Can we correlate it with electrode potential from the electrochemical series...if yes then how?
(3) What else can we predict from the CV curves? what other calculations can we made?
(1) Area under a CV curve is not necessarily or precisely correlated with reaction reversibility. Typically, you would look at one or two different metrics for that: i) the peak split between oxidation and reduction peaks for an ideally-reversible redox couple should be about 60 mV; and ii) shape and distortion of the redox peaks, in addition to their separation distance in mV, can be an indication that there is pseudo-reversibility or close to irreversibility. For the area metric, under a CV curve has units of Watts (Amps * Volts), and under a current vs. time plot it would have units of charge (Coulombs = Amps * time). It may be that you can loosely correlate comparative charges of the forward and reverse peaks, but I am not certain that is exactly indicative of CV reversibility.
(2) This I think I cannot easily answer for you. It may require more knowledge of your specific system that I do not have, and you may also need to look into literature to see if there is an explanation as well. Possibly this could indicate there is an additional chemical step that is consuming one of the products from an oxidation step such that it is no longer present to be reduced. Or, perhaps one of the oxidation reactions is entirely irreversible so there cannot be a corresponding reduction step.
(3) From voltammetry data there are some other kinds of analyses that are done, such as peak height via the Randle-Sevcik equation, diffusion coefficients, Tafel transformations (when it is appropriate), and scan rate studies. These are just a few general options, and I encourage you to investigate our RUclips videos (including previous webinars) in addition to the scientific literature if you need to see more examples of these processes/analyses.