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Electrodeposition of Bismuth, Bismuth Plating Baths

Q. Hi, I have basic knowledge of chemistry and I have been successfully copper electroplating/electroforming for some months now.

I've been for some weeks with the idea of bismuth electroplating on top of copper but I cannot find much information about it. I came across this paper www.nature.com/articles/s41598-023-28042-z and I have mainly two questions:
- I cannot get nitric acid where I live, can I replace it with sulfuric acid?
- This one is less important, but convenient. Can I replace bismuth (III) nitrate pentahydrate by bismuth subnitrate (BiONO3┬ĚH2O)?

Any other methods to accomplish the bismuth plating on copper is also welcomed.

jky albert
- Barcelona Catalonia
July 28, 2023

↓ Closely related postings, oldest first ↓

Q. What factors and precautions are involved in electroplating a surface finish of pure Bismuth onto ferrous and nonferrous metals? Are there any job shops that have the ability or experience with this task? Your assistance is appreciated.

Edward T. Reininger
Systems R&D; - Long Beach, California

A. You might want a copy of Dingley, et al, Plating and Surface Finishing 63(4), 26, 1978 for a review of bismuth plating, as bismuth plating is not a commercial process.
Lowenheim (Electroplating [affil link on Amazon]) mentions that Bi plating might have "some minor uses in the electronics and nuclear energy fields".

tom pullizzi animated    tomPullizziSignature
Tom Pullizzi
Falls Township, Pennsylvania

Electrodeposition of Bismuth onto Al

Q. I want to find some info about electrodeposition of Bismuth. Who can offer some pages which are about electrodeposition of Bismuth? thanks


Liu_xuelei red_a
tianjin university - tianjin china

A. Compared to say Nickel, not much is written about Bismuth. The anions are: perchlorates, chlorides, and (alkaline based) tartrates. All of the major plating books have something on plating the uncommon metals. Try Modern Electroplating by Lowenheim.


Fred Mueller, CEF
- Royersford, Pennsylvania

Dear Sir,

I have recently read your letter regarding information on plating Bismuth. We have developed an aqueous solution which will deposit Bismuth onto a magnesium base metal. This is a selective, electrolytic process that has so far shown good results.

Chris Helwig
- Valencia, California USA

Q. Hi guys,

I was thinking, what makes a good electroplating bath? Is there a design guideline on what type of substance is required besides the plating element? For example, the bismuth electroplating bath proposed below,

Chemicals Qty
Lactic acid, 0% 150 ml/l
Bismuth Nitrate 10g /l
Sodium sulphate 20 g /l
Nitric acid, 65% 50 ml /l

Operating conditions
Cathodic current density 0.3 A dm-2 @20-25 °C
Current efficiency 95-98%
Coating thickness 7.6 µm

There are 2 acids in the solution while a reducing agent(sodium sulphate). I was thinking how do people come out with the initial electroplating bath composition? Is the key requirement to have a reducing agent and the plating metal salt?

Jian xiang (Edwin) Pang
- Eastmidland, Nottingham, United Kingdom
November 9, 2010

"Modern Electroplating"
by Lowenheim
from Abe Books
or Amazon
[affil links]

A. It would take a book to answer your question.

A good place to start would be Modern Electroplating by Lowenheim published by Wiley.

Reducing agents serve no purpose in normal electroplating solutions and why do you think sodium sulphate is a reducer?

Very few metals deposit from simple ionic salts and I can think of none that plate from a nitrate bath which I would expect to give off ammonia [affil link on Ebay & Amazon] from the anode.

There are few practical applications for bismuth plating so finding a practical process may not be simple.

Have you considered PVD as a practical alternative?

geoff smith
Geoff Smith
Hampshire, England

Q. Thanks for you reply Geoff,

I did think of PVD as an alternative but it's rather expensive. From what I've read from books so far, the important factors include Bath pH, Temperature of bath and of course the plating bath composition.

The current trend would point to using of a salt, acid and sometimes a stabilizer. Another issue about electroplating is the distance between the anode and cathode. The closer they get the more conductive the whole circuit gets, while the better the plating?

Edwin Pang [returning]
- Nottingham, East Midland, UK

A. Hi Edwin

It might help if we knew what you want your deposit to do.

If you need a functional deposit, developing a viable plating bath is not a simple solution. Professionals expect to spend months in development with considerable lab backup. Well, I did, but you could get lucky.

On the other hand with a MP of 271° C, bismuth should be a simple job for PVD and easy to set up in a lab. You need a small vacuum chamber and a twisted tungsten wire filament that can be heated to red heat by a small power supply. Load scraps of Bi onto the wire and heat gently under vacuum until they melt and coat the filament and then increase the heat to evaporate. Take it gently or the Bi will fall off! The next step up is a W or Mo boat but you should not need sputtering equipment.

Even simpler, if someone in the lab has a SEM, they probably have a coater you could use for a trial. (a promise of beer may improve their generosity)

geoff smith
Geoff Smith
Hampshire, England

"Electroplating Engineering Handbook"
by Larry Durney
from Abe Books
or Amazon
[affil links]

A. Hello,
The question needs to be answered with Electrochemistry basics and applied electrochemistry, i.e., electroplating knowledge. Books like Electroplating by Lowenheim, Electroplating and Engineering Handbook by Kenneth Graham.

Electrochemistry by E.C.Potter etc must be gone through. Otherwise it will be like going in wilderness. For e.g. you incorporate a nitrate solution with nitric acid, NO3-ions will get reduced at the expense of metal deposition at the cathode! A very high concentration of metal ions means a very high nucleation rate and you will end up with a non-adherent deposit.For e.g., electrolysis of Silver nitrate solution will only produce non-adherent treeing!Sulphates will be a better selection as electrolyte. Solubility of the salt is an important consideration.Adding electrolytes to improve conductivity of the bath and additives generally organic compounds for better deposit qualities like brightness, etc. are to be investigated.Throwing power and cathode efficiency needs study. A literature survey for a decade (see chemical abstracts) will give a proper leads for further experimentation.

Subramanaian Ramajayam
consultant - Bangalore, India
January 5, 2012

Multiple threads were merged: please forgive repetition, chronology errors, or disrespect towards other postings [they weren't on the same page] :-)

Q. Is there any information on formulations for a bismuth bath?

Gilbert Alfaro
- Houston, Texas ,USA

A. Lowenheim's book called Electroplating has a formula for bismuth plating which uses perchloric acid, so it may be an effort to use it safely.

tom & pooky   toms signature
Tom Pullizzi
Falls Township, Pennsylvania

Q. Is it possible to electroplate a finish of Bismuth metal as a substitute for lead? What would be the procedure and/or does anyone know a company that plates with Bi?

Carlton Reininger
- LaCrescenta, California, USA

by Paul M. Tyler
from Abe Books
or Amazon
[affil links]

A. Bismuth is used as a substitute for lead in some solders and can be electrodeposited. It is, however, not a common process.

Lowenheim in Modern Electroplating suggested a bath of 40 g/l Bi2O3 with 104 g/l HClO4 and glue and cresol as additives. This is rather nasty as perchloric acid is prone to cause explosions. There is also a recommendation for NaBiCl4 with excess hydrochloric acid, but he concludes the perchloric acid bath is better for electroplating.

More recently a patent was granted for the use of bismuth chloride with various chelating agents; one such bath is 200 g/l potassium pyrophosphate, 35 g/l bismuth chloride and 10 g/l dextrin. The pH is adjusted with either HCl or NaOH, as required. Variations on this include the use of EDTA, with or without pyrophosphate, and gluconic acid as chelators. These baths can be: 1) EDTA 100-250 g/l; NiCl2.H2O 10-100 g/l; dextrin 1-50 g/l; pH 9-11; 2) 50% gluconic acid 100-300 g/l; NiCl2.H2O 10-140 g/l; EDTA 50-250 g/l;' dextrin 1-50 g/l; pH ~10, adjusted with HCl; 3) Potassium pyrophosphate 200 g/l; EDTA 150 g/l; NiCl2.H2O 48 g/l; dextrin 10 g/l pH 9-10. All these baths can be used either hot or at room temperature; if hot the ccd can be at least 50 ASF, but the colder bath prefers 25 ASF.

Bismuth can also be deposited by an electroless route. One prescription is: Bi salt 5-20 g/l; HCl 50-500 ml/l; Iodide 0-4 g/l; wetter <1 g/l; pH<1 temp 150±10 F. This uses an immersion time of 30 secs to 5 mins. Alternatively, dissolve 5g of Bi2O3 in 200 ml of HCl (conc.) and stir for 1 hour at 100 C. Add 100 g of 70% glycolic acid, with 100 g of N methyl pyralidone and 100 g monoethanolamaine. This is followed by 1 g potassium iodide. Dilute to 1 liter.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

A. Hello Carlton,

Bismuth can also be brush electroplated. We currently have a bismuth brush plating solution that was originally designed to plate onto magnesium alloys. The bismuth solution, like most brush plating solutions, has a different chemistry than conventional tank plating solutions.

Chris Helwig
- Valencia, California

Q. Hi,

I am trying to carry out an experiment that involves the electroplating of Bismuth on a layer of metal. The Bi electrolyte is prepared by mixing bismuth nitrate with DMSO (Dimethyl Sulfoxide). The electrodeposition of bismuth onto gold surface is quite successful but when I replace gold with titanium, there is little to no deposition. I have seen many posts concerning the difficulties with electroplating on Ti. Ti is chosen as the seed layer because it can be etched away easily so are there any other metals that can be better substitute for Ti (must be able to be etched away easily) in the electroplating of bismuth? Therefore, my question is how can I electroplate Bismuth onto Titanium? Are there any good references for the electroplating of bismuth? Furthermore, if bismuth were to electroplated into extremely narrow grooves, what are the approaches you would suggest?

Thanks for all the help.

Sean, Chen
McGill University - Montreal, Quebec, Canada

A. First of all, at what potentials are you trying to deposit bismuth onto titanium? What else does your solution consist of other than DMSO and bismuth nitrate? Titanium has a negative Redox potential, so it could be that you are oxidizing the titanium. I would guess though that you need to go to higher reduction potentials because there may be a large overpotential for the reduction of bismuth on titanium. Also, bismuth is very chemically sensitive so any etches that remove titanium are likely to remove bismuth as well.

Akram Boukai
- Pasadena, California, USA

Plating aluminum with Bismuth

Q. I need to coat aluminum with bismuth. I followed the non-electric method above with "5g of Bi2O3 in 200 ml of HCl (conc.) and stir for 1 hour at 100 C. Add 100 g of 70% glycolic acid, with 100 g of N methyl pyralidone and 100 g monoethanolamaine. This is followed by 1 g potassium iodide. Dilute to 1 liter."

This seemed to work quite well, although not entirely knowing what to expect I think it is not right. I was expecting a shiny metal like finish. It plates very black and then dries gray with a grainy finish. I tested continuity and there is none. Is there a special pretreatment, should I plate the Al with another metal first, etc?

Thanks for all the help in advance!

Jason Sanders
- Clarkston, Michigan, USA

Hi Jason. Yes, aluminum instantly forms a passive oxide layer, so it requires a special preparation cycle which usually involves immersion zincating followed by cyanide copper electroplating or electroless nickel plating before your final plating layer(s). Good luck.


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


Q. I had been looking for a method to plate with Bi, but it sounds like I need a different approach, as I am interested in a Bi or Bi - oxide(s) layer(s).

But I am also looking for a way to etch Bi and plate over Bi with other metals.

Charles Barnard
product designer - Menomonie, Wisconsin, USA
November 21, 2010

Multiple threads were merged: please forgive repetition, chronology errors, or disrespect towards other postings [they weren't on the same page] :-)


Want to avoid plating out bismuth in electro-recovery of precious metals

Q. Hi,
We are doing baseline studies, experimenting with an electroplating process of plating precious metals out of small heavily mineralized creeks. Using stainless steel plates for cathode and anode. Cathodes are contained in a cotton jacket. Plating a lot of bismuth out of these creeks. Running around two volts across the plates. What voltage potential does bismuth plate out at? Trying to discriminate it out as it is a mess to deal with in the chemical refining end of the precious metals. Thank you for any help.

We're firing the plate residue in a furnace, using a silver inquart and picking up the bismuth of course in the silver. Been dissolving it in Sulfuric Acid filtering off the precious metals and precipitating the silver back. A long way around to get rid of the bismuth.

Chuck Chase
mining and minerals - Baker City, Oregon, USA
April 29, 2014

A. Hi Chuck. I found a galvanic series that included Bismuth, and it was slightly less noble than copper. So your voltage sounds high since you want to keep bismuth from depositing. Can you possibly use a high surface area (sponge) copper cathode with tight anode-cathode spacing so you can reduce the voltage and make the conditions less favorable to the deposition of bismuth?

Is there any practicality to going through an ion-exchanger first, and then doing the electro-recovery from a regeneration/backwash that is more concentrated?


Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Chuck

Comparing electrode potentials is good in the lab if you know what is in the solution. Your creek water will have an unknown composition that could significantly complicate matters. Some metals co-deposit and complete separation may not be possible but you may be able to at least improve your yield.

As a simple suggestion, I would plate out a small sample in the lab while increasing the voltage in small steps and measuring the current. Plot a graph of volts v amps and, if separation is practicable, you should see a step where the bismuth starts to plate out.

If this works, a constant voltage rectifier is the next step.

geoff smith
Geoff Smith
Hampshire, England

Q. Hi,
I'm a university student and I need to deposit thick layer Bismuth (>20 µm) through electroplating on Au (or Cu) sputtered substrate. What are best recipes and operative conditions for this process?
Thank you for your collaboration.

My best regards,

Anna Maniscalco
- Palermo, Italy
October 23, 2017

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