I am trying to use a metal electrode in an electrochemical system in aqueous system. So I am not sure if this electrode work or dose NOT work. on the other words, I am not sure if it is corroding during applying voltage or NOT.
How I can detect the corrosion on this electrode?
Have a look at the pourbaix diagram and see if it is stable in the solution. You can also apply an extreme potential where you have for sure some corrosion. By that you can get an idea what is happening to the electrode if you do have corrosion also at a less extreme potential.
Thanks all of you Prof. Muralidharan and Luca for your information.
The thing is I am using Al foil which is surface treated (has a kind of conductive coating) on that to protect it from corrosion. I am gonna use this coated Al foil in aqueous solution. So, there is the probabilities for Oxygen evolution which can overlap with the corrosion if exist.
How can I distinguish between these reaction?
You mentioned I have to track any changes, BUT I am thinking maybe this changing coming from other reactions rather that corrosion of the foil...
Thanks,
NO oxygen evolution will occur in the potential ranges near OCP(Corrosion potential)
do anoidc polarization upto 200 mV away from OCP
Thank Dr. Muralidharan, But, How Can I find the exact value for OCP (corrosion potential)???
As soon as you immerse the alloy in the solution you follow the potential of the alloy - this is OCP( open circuit potential) it will vary with time
take the OCP is the steady potential attained after some time
OCP is the corrosion potential = what you calculate from the extrapolation of Tafel slopes is the pseudo corrosion potential ( as the surface has lost its virginity)
1) By following the variation type of OCP by time it will be possible to detect the corrosion, passivation, passivation - dissolution, dissolution-passivation,...
2) See Luca Bardini and others discussions.
Thanks Habib,
the thing is I am working in a water-based solution as electrolyte and many other side reactions would happen during applying positive voltage at the metal surface.
How can I distinguish between them all side reactions and tell which one is more probable to be due to corrosion.
Anyways, could you send me any link to help me find those discussion you just mentioned?
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