I am working on corrosion monitoring of steel embedded in concrete? Different authors adopt different cell geometry. I am unable to find the science behind the cell configuration. Kindly help
When i worked with three electrode set up, the distance between the reference electrode (salt Bridge) and the material (working electrode) did matter but the Position of Counter electrode had no significant influence on the result.
The distance effect was also electrolyte, material and its geometry specific. For example with steel (303ss) the effect was very negligble but with aluminum and its alloys the difference of 2mm had significant effect.
I know this is not an answer for your question but its just my experience !!!!
I think it deals with resistance between the working electrode and the referece... not quite sure though!!!!! in the IvsV curve the V is potential diff between Ref and working electrode. I think the distace would have influence on the resistace and thus PD...(just guessing).
It is better to place the reference electrode and the working electrode as close as possible; this gives the lowest resistance to the system, thus a more accurate result from your electrochemistry (lower iR drops from Galvanostatic measurements and no odd tails during voltammetric). Where you place the counter-electrode within the system does not matter.
The best configuration should give more accurate results but I would not image will affect the corrosion rate.
Reaction between counter and working electrode, the distance between the two is very important.
Dear Selvakumar, Can you please eleborate your point? Where should i look for with respect to the literature?
Reference electrode will helpful to find the potential of your working electrode (e cell # e cathode - e anode) whereas the reaction will take place working and counter, normally in your three electrode system counter should face to working electrode, where as the area of counter and working electrode is important for the corrosion measurement.
you must put the sample (the working electrode) in the middle, the reference electrode very close to him to measure the exact Eoff potential at the interface, the counter electrode its role is to close the electrical circuit ( electron's passage) without reactions with the solution then you have to put it at a little distance from the sample.
Yes, distance between the three electrode and their positioning is very important and it should be kept as minimum and at fixed position throughout the experiment. It is better to place the electrodes in triangular pattern with working electrode in the middle.
Also for more information on electrochemical analysis you can refer to Analytical Electrochemistry by Joseph Wang.
working electrode is placed between the reference and counter electrode. three electrodes are placed in such way that equilateral triangle, ie, electrodes are equi-distance from each electrode and in triangle manner.
Working electrode should be very close to reference electrode as possible as. dostance between working electrode, reference electrode and counter electrode should be minimum and at fixed position.
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