How can I use numerical integration to properly determine the area of cyclic voltammetry data?

Hi Everyone,

I have been working on a script that performs some analysis of Cyclic voltammetry data according to 'Dunns method'

I have uploaded the full code and data in a Zip for you to properly peruse.

In short:

I am trying to find the ratio between the area of two sets of data. I'm currently using the Trapz() function to calculate both areas.

The problem is that when I plot both sets of data on the same figure (the 3x2 subplot), the ratio appears like it should be greater than 0.5 but instead is consistently too low. I am using absolute value for the negative terms in my data because I want to include all relevant data, is there a bettter way to achieve this ratio?

Answer 1

[Nipun]

Hi Mitchell,

I understand that you are trying to evaluate the ratio between the area of the cyclic voltammetry data of the two datasets using the Trapz() function.

If you're finding that the calculated ratio is consistently lower than expected, there could be a few potential reasons for this discrepancy. Based on the attached code, I have a few recommendations:

1. Using the absolute function carefully: The direction of current might influence the sign of the value. For example, current in the opposite direction to reference may be taken as negative and thus might not be suited as an argument to absolute function.
2. Trapz function: Ensure that the integration using the trapz function is being applied correctly. It might be helpful to plot the individual curves and the areas being integrated to visually inspect whether the integration is capturing the correct regions.
3. Scan Rate and Iteration: Check the values of scanrate and iteration. These parameters influence the calculation of K1 and K2, and if they are not chosen appropriately, they might affect the ratio.
4. Polynomial Fit: Inspect the polynomial fits, especially in regions where the potential is changing rapidly. A poor fit might lead to inaccurate slope calculations.

Hope this helps.

Regards,

Nipun