Authoritative Answers, Fun, & Aloha -- no cost, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Home /
Site 🔍
pub     mobile?
Metal finishing Q&As since 1989


Is Cathode-only plating possible for metal recovery

Is it possible to plate using only a cathode with a direct currect power source if the amperage/voltage is high enough?

I have a Nitric/Hydrofluoric acid etch bath with dissolved metal ions and was just wondering if it is possible to "pull" these Ions out of solution without a complete current since having an anode would only dissolve more metal ions. Thanks.

Randall McDaniel
chemical process tech - Naples, Florida, USA
April 16, 2008

Hi, Randall. No, that's not possible -- but you may find that a platinized titanium anode does not dissolve. In general it is difficult to plate out of nitric acid because plating is a reduction process and nitric acid is a powerful oxidizing agent.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
April 18, 2008

April 18, 2008

I once attempted to plate nickel out of a nitric acid based nickel stripper. I succeeded in plating out the traces of copper that were in it, but no Ni plated out though the concentration was in excess of 50 g/l.

This is because of what Ted pointed out - the nitric is a powerful oxidizer. The preferred cathode reaction winds up being the reduction of nitrate to nitrite, rather than the reduction of Ni2+ to Ni 0.

If the metals you are trying to plate out are far down enough in the electromotive series, you may have luck. Compare the standard potential of the reduction of the metal ion to the undesired NO3- ---> NO2- potential. This will tell you whether thermodynamics is on your side, or not. Water may flow in many ways on a hillside, but it will not flow uphill. :)

You may also use graphite as an inert anode.

dave wichern
Dave Wichern
Consultant - The Bronx, New York

Hi, Dave. Very informative post, thanks. As you see, I had some understanding of the issue, but not to the depth you gave us.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
April 18, 2008

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
& Software

About/Contact  -  Privacy Policy  -  ©1995-2024, Pine Beach, New Jersey, USA  -  about "affil links"