Suppose I want to calculate the diffusion coefficient for an OER which is not only diffusion limited but also dependent on adsorption of redox species. Will it be correct to use Anson equation? The CV of the sample is attached herewith.
Yurii V Geletii, Sir I understand that we have to use chronocoulometric measurements, but my question is whether we can use it only for a diffusion limited process.
Yurii V Geletii Sir, I had plotted Ip vs square root of scan rate and found the slope to be linear . The value was approximately 0.59. However, CV (included here) shows that the system is not completely reversible and despite having a linear relationship (Ip vs square root of scan rate) we cannot use the Randel Sevcik equation to calculate diffusion coefficient.
That’s why I have attached the graph to know whether Anson equation can be used for this particular sample if it exhibits such CV pattern.
I humbly request you to pour some insights into it.
I have no ideas about your system and therefore can't discuss the hypothetical problem. First, collect the chronocoulometry data and see what happens.
Chronocoulometry is used to study the kinetics of chemical reactions, diffusion processes, and adsorption. In this technique, a potential step is applied to the electrode and the resulting cumulative charge vs. time is observed.
from
https://www.gamry.com/Framework%20Help/HTML5%20-%20Tripane%20-%20Audience%20A/Content/PE/Experimental_Techniques/Chronocoulometry/Purpose.htm
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