The copper cathode will plate some silver initially, but after that will not be substantially different than a silver cathode.
That is, as long as you are not using polarity switching. With no polarity switching, there is no more loss of silver than in the case of two silver electrodes, not enough to be of any significance. I wouldn't leave the electrodes in the water after completing the electrolysis. It may have some negative effect eventually. Dan On Thu, Sep 9, 2010 at 10:37 AM, Marshall Dudley <mdud...@king-cart.com> wrote: > The production of copper hydrite in EIS is an interesting analytical > problem. The hydrate is rather unstable, and likely will react with Silver > hydroxide producing colloidal copper, colloidal silver and H2O. If this is > correct then using copper for the cathode would produce a combination of > both colloidal copper and silver. Then the colloidal copper would likely > react with silver oxide producing copper oxide, and additional colloidal > silver. Copper oxide is insoluble, and thus would likely form a > precipitant. > > But I think the biggest problem with using copper as a cathode is that > copper will reduce silver hydroxide and silver oxide, so that the ionic > silver will plate out as silver on the copper, removing the silver from > solution as you are making it, reducing efficiency significantly. This > reaction can be confirmed by putting some copper into some EIS and noting > that it turns silver colored over time. > > Marshall > > Dan Nave wrote: >> >> The cathode (in this case the negative terminal) can be copper if you >> are not polarity switching. >> >> The anode (in this case the positive terminal) must be silver. >> >> You can see I don't agree with cking, as usual... >> >> Dan >> >> >> >> On Wed, Sep 8, 2010 at 5:28 PM, David AuBuchon <aubuchon.da...@gmail.com> >> wrote: >> >>> >>> Is there any reason everyone uses silver for the cathode? I can >>> understand >>> if people were reversing the polarity. But when things only go one way, >>> does it matter what the cathode is made of? Could it just be copper >>> wire? >>> >>> Also, isn't the surface area of the cathode important. With the anode, >>> more >>> surface area reduces the density of a layer of silver ions coming off, >>> combining with hydroxide ions. At the cathode end, isn't there a dense >>> layer of hydroxide combining with incoming silver ions? >>> >>> Thanks, >>> ~David >>> >>> >> >> >> -- >> The Silver List is a moderated forum for discussing Colloidal Silver. >> Rules and Instructions: http://www.silverlist.org >> >> Unsubscribe: >> <mailto:silver-list-requ...@eskimo.com?subjectsubscribe> >> Archives: >> http://www.mail-archive.com/silver-list@eskimo.com/maillist.html >> >> Off-Topic discussions: <mailto:silver-off-topic-l...@eskimo.com> >> List Owner: Mike Devour <mailto:mdev...@eskimo.com> >> >> >> >> >> >> >> > >
