I just want to mention the second possibility of determining the EASA by integrating the CO peak instead of Hupd. Both methods can be easily found in literature.

After you perform the cyclic voltammetry in a acidic solution, you integrate under the hydrogen desorption or adsorption (the peaks occuring in the -200 mV to 0 mV vs. SCE). Then you will take that area under the curve which is in micoC units and convert to cm^2 with a factor of 210 cm^2/microC (this constant is generally used for metals but it comes from the Pt). This is then your ESCA.

In short:

From a set of CV experiments assuming reversibility you can represent the current vs the squared root of the scan rate. Then you can perform a linear regression and easily determinate the slope. From the Randles-Sevsik equation it is possible to calculate the ECSA if you know the diffusion coefficient and the number of electron transferred.

I would be happy if you ask me for more details.

Reference: Bard et Faulkner, Electrochemical Methods.

Regards

I just want to mention the second possibility of determining the EASA by integrating the CO peak instead of Hupd. Both methods can be easily found in literature.

Hupd and CO stripping are quite commonly used for determination of the EASA. But in order to choose the best method the main question is which working electrode are you using? Since if it is Au for example, there is no Hupd peaks.

Hi,

We have a article here at ResearchGate describing the issue of the determination of the electrochemical active surface area of solid electrodes (DOI: 10.13140/RG.2.2.30813.61923). In addition, we developed a free software that allows us to estimate the active area from cyclic voltammetric experiments. Best regards.

Fabrizio,

Yes, the software is FREE OF CHARGE!

You can download it at the following website:

http://www2.feg.unesp.br/#!/paginas-pessoais/fisica-e-quimica/prof-eduardo-goncalves-ciapina/english-version/software-for-the-determination-of-real-surface-areas-of-solid-electrodes/

The software was written using JAVA, so you need an updated version of JAVA (by Oracle) in your computer. Just double-click the .jar file and the software will be running and read to use.

If you have any questions, please let me know, OK?

Best regards,

Eduardo Ciapina.

@ Milutin Smiljanic , I am using two different working electrodes, (i) graphite discs and (ii) titanium foil in different experiments. Will CO adsorption / desorption peak be accepted in case of graphite? Also, from where exactly does the CO adsorption / desorption peak comes from

(What is the source of carbon in electrolyte)? [I am using 0.5 M NaOH as electrolyte].

Sorry but I understand your question Sir, so I dare to bring you some elements of answer:

1.The CO-adsorption would come from some CO-gas that you will inject into your electrolyte, and adsorb at a constant potential on the working electrode. You will then need to degas your electrolyte with N2, argon or an inert gas before performing the voltammetry.

2.After performing the voltammetry oxidation of this adsorbed carbon monoxide to carbon dioxide you will have a coulomb value. Your next question (anticipated by myself) will be: "what to do with that value for both working electrode types ?"

And here comes the point 3...

3.For interpretation of such a value on a given electrode you need a specific charge, expressed in C m-2 (and more appropriate µC cm-2). For titanium electrode you should find one tabulated in the literature, as models of adsorption (monolayer, one Ti per CO, two Ti per CO, and so on) and the crystalline structure of titanium are known. For graphite the problem is different, as, to the best of my knowledge, no such a specific charge can be calculated precisely (possible intercalation, nature of the graphite, alien atom present in the material) and that graphite itself is generally oxidised itself by simple exposition to air and distinguishing both oxidations would be difficult.

So the answer to "would be CO-adsorption accepted in case of graphite ?" is obviously that "it will depend of what your are deducing from your experiments". And maybe choosing another probe molecule could be of some help.

Tell me if I have answered some of your questions and if you have any further ones.