Sciencemadness Discussion Board

Reducing agents for Electroless Nickel plating

Imakethings - 27-3-2013 at 17:36

I've been fiddling about with electroplating and doing a bit of reading. Recently I've come upon a stumbling block.
I'm wanting to make an electroless nickel bath, but the reducing agent for the bath has become a problem.

The most common industrial chemical used is sodium hypophosphite, which gets used in meth production. So finding it isn't an option. Making it is just as questionable.

So the most common reducing agents are:
Sodium Hypophosphite
Sodium Borohydride
Dimethylamine borane (DMAB)

So any suggestions or thoughts on these or any other reducing agents? I'm doing this on the cheap, so the advice of going out to buy something doesn't really work for me.

Mixell - 27-3-2013 at 18:16

Is it forbidden to ship sodium hypophosphite to the US?

Imakethings - 27-3-2013 at 19:39

Just about all phosphorus compounds are controlled substances in the USA. It's a bit annoying since I actually want to use it for something other than Meth.

I'm thinking that I should be able to make the Sodium Borohydride, but I'm not 100% sure I can. I'm thinking I can manage it using Boric Acid, I just need to go from H3BO3 to NaBH4 still pondering on the best way to do it.

elementcollector1 - 27-3-2013 at 20:07

Not really, phosphoric acid and sodium orthophosphate are both unregulated.

Imakethings - 27-3-2013 at 20:11

So is trisodium phosphate, but I'm still not sure on what would be the best way to net a good reducing agent for plating.

Wait... same thing different name.

[Edited on 28-3-2013 by Imakethings]

Mixell - 28-3-2013 at 07:39

I've heard the customs let packages of up to 100g to pass, but I think you need to verify it.
There's a supplier that ships it to my country, if you want I could send you 100g for 10$ (providing you're willing to take the risk).

Imakethings - 28-3-2013 at 14:28

I'm not though, there should be another way to make something works. Besides Sodium hypophosphite is only one of the options available to me.

I'm more interested in the sodium borohydride honestly.

Imakethings - 28-3-2013 at 18:34

Has anyone used the Bayer process to make NaBH4?


I'm thinking:

Na2B4O7 + 16 NaHSO4 + 7 SiO2 → 4 NaBH4 + 7 Na2SiO3

At approx 500-600C in a reducing atmosphere (fuel rich, no methane source, so propane will be used).
ceramic graphite crucible.

I've got a propane furnace that can reach 1500C, but I think that would be a bit much. I'll be using a smaller furnace to get to the 500C temperature needed to start the reaction.

Now, I know I didn't include the 16 SO4 in the above reaction because I'm honestly not sure what it's going to do at higher temperatures. One of my concerns is that the NaHSO4 will decompose around 400C into Na2S2O7 + H2O, so I'm not sure it will work.

Thoughts? Input? Ideas? Am I going a bit far?

[Edited on 29-3-2013 by Imakethings]

Imakethings - 28-3-2013 at 19:23

NaOH in place of NaHSO4 maybe? It won't decompose at temperature and lose the hydrogen.

Current plan:

10g Borax
260g NaOH
85g Diatomaceous earth

The changes in the amounts used is to compensate for any possible impurities in the reagents used and other molecules present in the mix that might misbehave.
Under ideal conditions I'd get about 40g of sodium borohydride out of this. I'd be happy with 50-75% honestly.

After a bit of reading and thinking, propane is not the best power source for this reaction. I'm going to build a small electric furnace for this (I've been meaning to make one for some of my other hobbies anyway).

[Edited on 29-3-2013 by Imakethings]

Imakethings - 30-3-2013 at 07:25

used only 25% of the proposed reactants I listed since I opted to use a couple smaller older ceramic cups in lieu of my fancy pants graphite crucible.
The thermocouple I normally use decided to crap out on me, so temp was unknown. I did a rough calibration of temp based on temper/oxidation color on a chunk of steel, I dialed it in somewhere between 600 - 700C then added stuff and brought it up to temp over an hour.

The result is a solid white material that dissolves completely in water. lacking any pH indicators for titration at present I can only report that the stuff is basic based upon its energetic rxn with HCl.

Now I need to figure out the best way to seperate the sodium silicate and sodium borohydride, currently looking thinking of solubility.

Imakethings - 3-4-2013 at 05:28

Well I confirmed the presence of sodium silicate by adding ethanol to the mix and getting silica gel precipitating out. So this suggests I'm close since that is one of the products I expected.

Imakethings - 8-4-2013 at 08:03

While I have found a cheap way to make silica gel (derived from the above process), I didn't make NaBH4 in a high enough concentration to do any good.

I did find that hydrazine (N2H4) might be doable using a modified peroxide process, but I'm hesitant to try that one due to the setup. High temp stuff I'm fine with, that one I'm not sold on.

So any suggestions on other reducing agents?