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Platinum & Platinum Black Plating

Q. Hi

I am working on Pt electroplating with Q salt. During coating, the concentration of Pt reduces as Pt forms on a sample. I measure Pt consumption according to the weight change of the sample and replenish the solution based on the measured data.

Is there any other methods to accurately measure the Pt concentration in the solution? I mean a practical method that can be used in the industrial line of Pt coating (such as titration, using baumé meter or ....). Could you please help me with detailed information about the method?

Thanks for your attention.

Mohammad H Esnaashary
Engineer - Tehran
July 22, 2024

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⇩ Related postings, oldest first ⇩

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Q. I am looking for any information on electroplating platinum for microelectronic applications. The application requires a smooth deposit less than a micron thick.

Bob B [last name deleted for privacy by Editor]
- Semitool
1998

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Platinum black electroplating

Q. I'm looking for information on platinum black and platinum black electroplating. I have been having trouble locating research articles and books pertaining to this topic.

Any help would be appreciated.

Thanks.

Ron Kushner
- Sylmar, California, USA
2001

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RFQ: I would like to coat Platinum on a Ceramic Tube. Would please suggest me any company working in mass production related to this process?

Dr. Loka Subramanyam Sarma
- Taipei, Taiwan, R.O.C
2002

Ed. note: Sorry, this RFQ is old & outdated, so contact info is no longer available. However, if you feel that something technical should be said in reply, please post it; no public commercial suggestions please ( huh? why?)

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Need platinum black thin film deposited into metal sponge

RFQ: I am looking for a source for plating a thin film of platinum black into the pores of a metal sponge.

Tony Iacovelli
director of R+D - Asheville, North Carolina, USA
2003

Ed. note: Sorry, this RFQ is old & outdated, so contact info is no longer available. However, if you feel that something technical should be said in reply, please post it; no public commercial suggestions please ( huh? why?)

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Q. I am trying to do platinum black electroplating using ysi 3140 platinizing solution. But I get either clustered or non uniform platinum black coating. Can anybody suggest, how to do a uniform platinum black coating.

Ajay Vikram
alabama university - Montgomery, Alabama
2005

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How to get platinum-rhodium coating on molybdenum metal

We wish to obtain a coating of platinum or Pt-Rh alloy on cylinders made of molybdenum metal. The parts will be exposed temperature of 1600 - 1650 degree C and will also come in contact with molten slags, fluxes and glasses. The components are to be used for measurement of high temperature viscosity of melts. Is it possible to have electrolytic deposition of platinum or Pt-Rh alloy, or deposition from some molten salt bath?

Somnath Basu
Jamshedpur, India
2006

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Q. We are looking into the possibility of selectively plating a small section of a stainless steel rod (both 316L or duplex Stainless steels are being considered) using platinum. Are there any experiences (both positive and negative) that we should be aware of?

Mike Turner
Chemical Manufacturing - Dobbs Ferry, New York
2006

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Platinum plating for high voltage (~1000V) electrophoresis

Q. Hello,

I'm a research engineer in a biophyics lab and I'm interested in plating small (1cm^2) electrodes with platinum for a high voltage electrophoresis application - separation of DNA in a conductive gel matrix (such as agarose or polyacrylamide with Tris Borate EDTA buffer) for biotechnology applications. From past experiments with solid Pt electrodes I expect the required current densities during operation of the plated electrodes to be on the order of 50mA/cm^2. I would like to achieve a coating that is as durable as possible, as the electrodes will need to be cleaned regularly. I am also interested in plating Pt-black, as the higher surface area might offer advantages, though this is not a critical requirement.

I've spent the past month experimenting with hexachloroplatinic acid and tetraammine (5Q) plating baths to plate platinum onto stainless steel (hexachloroplatinic acid) and copper (5Q bath). I've had the best success with the 5Q tetraamine bath, which I have prepared according to a paper published by W. J. Basirun (Studies of platinum electroplating baths Part IV: Deposits on copper from Q bath. W.J. Basirun et. al. J. Appl. Electrochemistry, 26 (1996) 873-880): 26mM Pt(NH3)HPO4 + ~30mM sodium phosphate buffer, buffered with NaOH to pH10.4 at 95C. My bath is 40mL of this solution in a 60mL glass beaker [beakers on eBay or Amazon [affil links] sitting on top of a stirring hot plate, with stirring effected by a teflon-encased magnetic stir bar and the temperature is kept between 92 - 96C (approximately).

My electrodes are paddle-shaped pieces of copper (99.6%) waterjet cut from 0.015" thick shimstock and are approximately 0.5cm x 1.5cm. I prepare the surface by sanding with 1200 grit emery paper, washing with ethanol, and then electropolishing in phosphoric acid (522g/L) at ~2V for 10 minutes (current density ~40mA/cm^2) until the surface is shiny. I then rinse in deionized water, dry with N2 and immerse in the plating bath.

I use a piece of platinum wire as a counter electrode, bent in a saw-tooth shaped ring surrounding the copper working electrode at a distance of ~2cm. I do not have a reference electrode and merely apply a potential from an adjustable supply across the two electrodes, and monitor the voltage and current with multimeters. I have used this configuration to deposit both shiny (1.9 - 2.4V) and black (2.3 - 2.5V) platinum with good success - the adhesion is very good and the plate is difficult to remove. However, when I run the electrodes in a strong salt solution at ~40mA/cm^2 (2.5X TBE to achieve high currents at ~30V, for testing) I notice that there are small blue nodules left on the surface of the plated electrode. These deposits are the colour of copper sufate and I am certain that they are ionized copper from the underlying metal. If I can stop these deposits from appearing, I think I will have accomplished what I need to for this proof-of-concept design.

I have a number of questions that I have not been able to answer by looking through literature. I have little knowledge of chemistry, electrochemistry in particular, but I have found your site quite useful thus far and I would like to thank you in advance for any assistance.

In no particular order...

1. What is the 'efficiency' of a bath, in terms of the amount of Pt that can be plated out of it, compared to the amount of Pt it contains, if such a number exists? Is there a surefire way to tell that you've depleted your solution?

2. Is there something inherently uncontrollable about using a two electrode system? If so I'd appreciate any advice on setting up a three electrode system.

3. Are there tricks to ensuring that the plated Pt will have no cracks through to the base metal, if I am not worried about the appearance of the finish? Do alternate layers of Pt black / shiny Pt help?

4. Does operating the plated electrode at high voltages and currents cause damage to the plating? (We currently use solid Pt wire electrodes [the standard for such instruments] and have not had problems with electrode breakdown.)

5. Is there a better choice for base metals, given that my constraints are fairly loose (good conductor, preferably resistant to corrosion as part of it will likely be unplated)?

6. For my application (high voltage, high current densities, in salty buffers), is there a metal other than Pt that might work? (We haven't spent much time experimenting in this regard, but found Pt to be the only metal to work).

7. Is there a way to replenish the Pt in the baths to get around possible problems of bath efficiency?

8. I always encounter references to Pt gauze for a counter electrode; should I be going in this direction as well?

9. Is degassing/deoxygenating important, as I have seen references to it?

This project is currently in a prototype phase, but this is the last major problem to be worked out prior to production. I am keen to speak with companies that specialize in this sort of process, and I contacted four of them previously, but have not received any responses.

Thank you,

Dylan Gunn
Scientific Engineer - Vancouver, British Columbia, Canada
May 27, 2008

A. Dylan

Thanks for a clearly worded and detailed question. It is a rarity.

I do not believe that you will easily get acceptable results by following published papers.

There are many potential problems with your method. As examples; no plater would for choice, use abrasive paper, degrease with ethanol (a poor grease solvent) dry before plating etc. In addition, plating onto stainless steel introduces many other problems and requires special processing to get adhesion. Forget reference electrodes. Platers operate at a predetermined current density, we are usually only interested in voltage for anodising processes.

The plating industry has spent many man/years on developing processes which work reliably. I believe that you could find better use for your research time than trying to emulate them.

Which leaves you with the next problem, finding a suitable supplier.

On the 'home' page go to 'chemicals' then 'Search engine' and enter 'Platinum'.

Your electrodes are so small that any of the precious metal supply houses could probably be persuaded to make a couple of samples for a good cause.

If you are still interested in the technology try "Modern Electroplating" Lowenheim, John Wiley & Sons inc. [on AbeBooks, eBay, or Amazon affil links]

Geoff Smith
Hampshire, England

A. Hello,

You have a very complicated system.
We do Pt plating (0.0007" thick) first and then it is diffused.

Jose Castellanos
- Minneapolis, Minnesota

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Q. We have been using an acid (pH3) ammonium sulfamate bath with diamine platinum sulfamate complex for two years. It seems very temperamental to pH, weekend storage temperature, trace contamination and with all that I can't get it to last more than six months. Even with Barium treatments to drop out sulphate, which forms from the sulfamate hydrolyzing from elevated temperature and acidity at anodes.

Can anyone tell me how to make the complex last longer? It really makes a beautiful deposit when it wants to. The complex that drives the deposit is definitely not the advertised (NH4)2Pt sulfamate. It forms from this over time and under the right temp., pH, density and balance of sulphate. Does anyone have some experience they would like to share?

Ronald Graf
- Claymont, Delaware
October 12, 2010

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Q. I am experimenting with plating for neurological studies and am having trouble finding source of Platinum black on the web. Can anyone help?

Update: I have found suppliers but I still need information on how much PtBlk/liter to use when I plate a Pt electrode. I have read several papers, (Mareese, Feltham/Sriro, Mills, Desai, etc.), they all talk about the plating solution, (typically Cloroplatic acid and a lead compound), but none indicate how much Platinum Black they used.

Jerry Gregoire
engineer - Bozeman, Montana, USA
October 18, 2010

Thanks for your response. One of my pitfalls was thinking that platinum black needed to be added to the bath rather than the Pt being reduced from the chloroplatic acid.

Jerry Gregoire
Electronics - Bozeman, Montana, USA

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Selective Plating using Platinum

Q. I was using Rhodium pen plating solution for plating on gold jewelry, but price of rhodium is very high, so I decided to make platinum pen plating solution. Can I use platinum metal dissolved in Aqua Regia or any other idea. Please suggest any idea.
Thanks

Babu R Cherayath
- Kochi, Kerala , India
November 15, 2022