If You talk about electro depositing (or electroplating) of metals out of a solution then look at the ionic form :Me+(++) witch means that the metal ions are charged positive. They are attracted towards the negative electrode where they should be reduced to Me thus catching an electron from the electrode. In the ideal case the reduced metal ions will form a coherent metal film. For cleaning we want to remove the outer layer of the metal electrode. Applying a positive potential will cause the surface to 'oxidize so the metal will form ions witch go into solution ( the opposite process) leaving a clean surface. About the cleaning: often the generation of gas on the electrode is also used as cleaning technique ( hydrogen at the cathode or oxygen at the anode. There are some risks involved like inclusion of Hydrogen witch can lead to embrittlement .
In all these cases we talk about two electrodes in a solution having a potential difference or tension over them. An other way to describe this is using the halve cells with there Nernst potentials
I suppose you talk about electro-deposition?
Selectiv attraction of anions or cations, depending on the role they should play?
which reaction is aimed at which surface..
following the potentials may tell you the state of the surface..
not an expert in that field.
I am thinking if the sample works as a cathode(-) and potential is positive then the deposition will take place. However, if the sample works as an anode positive terminal then the anode will lose electrons which will help in cleaning
If You talk about electro depositing (or electroplating) of metals out of a solution then look at the ionic form :Me+(++) witch means that the metal ions are charged positive. They are attracted towards the negative electrode where they should be reduced to Me thus catching an electron from the electrode. In the ideal case the reduced metal ions will form a coherent metal film. For cleaning we want to remove the outer layer of the metal electrode. Applying a positive potential will cause the surface to 'oxidize so the metal will form ions witch go into solution ( the opposite process) leaving a clean surface. About the cleaning: often the generation of gas on the electrode is also used as cleaning technique ( hydrogen at the cathode or oxygen at the anode. There are some risks involved like inclusion of Hydrogen witch can lead to embrittlement .
In all these cases we talk about two electrodes in a solution having a potential difference or tension over them. An other way to describe this is using the halve cells with there Nernst potentials
in most case, metal electrodeposition occurs at OPD regim (over potential deposition) . indeed using negative potential is recommended to deposit metals. Inversely, to clean the electrode surface, we use the positive potential for dessolving all impurities particularly for metals.
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