[PhotoElectroMaterials]

Dear everyone

In my experiments, I am using a potentiostat with a three electrode configuration.  The reference electrode is Ag/AgCl. 

In this case, I am applying a potential of +0.1V to the anode to carry out the oxidation reaction.  However i am also studying the reaction which is taking place at the cathode. 

What i want to know is the potential of the cathode when i apply +0.1V to the anode.  Is there anyway to measure it?

Can i assume that it is the opposite of the potential applied at the anode (i.e. -0.1V)?

Please give me your inputs.

Thanks
 

[vex]

Your assumption has to be true for a three-electrode geometry. The potential "at" the working electrode really describes the potential difference between the working and auxiliary/counter electrodes, so the fact that there is any potential at all at the working electrode necessitates the equal but opposite potential at the other electrode. The reference electrode is there so that you, knowing the gap between your other two electrodes, can pin their potentials somewhere in absolute energy space.

Of course, all of this is only formally true; there are a hundred complications that can lead to fluctuations in the in situ potential, but I think delving into that is more complicated than what you're looking for (also more complicated than what I'm familiar with  ).

Good luck!