I have noticed that in some cases CV profile is not a closed cycle, instead there is a cut. Why it happens?
Can it be a material propertiy also?
Do you have a current cut-off for the CV?
With autolab software there is an option to stop the CV if current reach an input value.
However, I agree with Michael, we need more information to help you.
Dear Jordi Carrillo Abad and Michael Y. Wong,
Please find the attached image. It is a CV of metaloxide/graphene composite.
Dear Mohit, your CV is perfectly complete.
The differences between the initial currents and the final ones observed close to 0V are related to the processes occurring on your working electrode. It seems that at 0V an oxidation phenomenon happens. Have you tried to do an OCP to determine your start potential?
Can you please elaborate the process occurring on working electrode as you mentioned? which oxidation you are talking about?
How to get this open circuit potential?
I used following setup
Glassy carbon as working electrode
Ag/AgCl as reference electrode
Pt electrode s counter electrode
The open circuit potential (OCP) is the electrode potential in which the current is zero. I don't know what kind of software are you using but in autolab software there is an option to determine it and stablish it as start/end potential in your CV.
With the data you provide us I don't know the reaction taking place on your working electrode. What is your electrolyte composition?
the study was performed in 1 M Na2SO4.
please elaborate "the processes occurring on working electrode in my case", as you mentioned above.
What is the rate (V/s). Also, can you apply 2 more rates (1.slower and 2.higher) ?
Your first reverse potential is 0.7V or -0.7V ?. However with that electrolyte it seems that you are generating hydrogen only. If you go from 0V to -0.7V first, the peak close to 0V may be related to a desorption of the hydrogen generated previously. On the contrary, if you go from 0 to 0.7V I don't know to what may be it related.
Do you pretreat your working electrode before each experiment?
I suggest you to stir your solution to see if the peak remains or not. In addition, I agree with Prof. Ioannis, you should modify your scan rate to observe its influence on your CV.
Finally, if peak remains you should modify your electrolyte (pH and Na2SO4 concentration) in order to see if the peak is modified.
So, dear Mohit Saraf, your Cyclic Voltammetry cycle "is not complete" mainly due to that high rate, i.e. due to transient (decaying) currents. If possible, apply, please, some slower rates (say a minimal list of rates : 50mV/s, 10mV/s, 5mV/s and 1mV/s).
Dear Mohit Saraf, i would like to know which cycle number is the CV that you are showing and hoe many cycles have you recorded. Could you also provide us with the CV of cycle one before and one after this CV cycle number.
Dear Adhidesh,
Why there is a difference between first and second or next CV cycle at same scan rate?
Dear Mohit,
There may be differences associated with the reversibility or irreversibility of the processes involved in your system, such as the passivation of the WE, etc.
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