goldandsilver123
Well-known member
- Joined
- Aug 11, 2015
- Messages
- 203
Hello,
I'm trying to make a rhodium plating bath, but the layer deposited is darker than the solution that I bought.
The rhodium I started with was already dissolved, a person gave to me because he tried to make this bath several years ago and didn't succeeded. The solution was analysed with AA and by the analysis it was 99,9% Rhodium in relation to metal cations.
The solution was reddish pink, what I assume it was from a pyrossulfate + chloride fusion. I neutralized it to pH 7,5 with potassium hydroxide and additions of hydrogen peroxide, this was boiled for 1 hour, then it was filtered.
To the hydroxide I added enough distilled water and sulfuric acid to make a 2 g/L Rhodium and 9,2 g/L H2SO4.
Do anyone have a clue?
The current draw was the same in both baths and no there was no development of bubbles in the piece. One time I over added the sulfuric and got an darker deposit with bubble development in the cathode.
Here's some pictures:
Left sample is the one I made, and the right one is the one that I bought.
I'm trying to make a rhodium plating bath, but the layer deposited is darker than the solution that I bought.
The rhodium I started with was already dissolved, a person gave to me because he tried to make this bath several years ago and didn't succeeded. The solution was analysed with AA and by the analysis it was 99,9% Rhodium in relation to metal cations.
The solution was reddish pink, what I assume it was from a pyrossulfate + chloride fusion. I neutralized it to pH 7,5 with potassium hydroxide and additions of hydrogen peroxide, this was boiled for 1 hour, then it was filtered.
To the hydroxide I added enough distilled water and sulfuric acid to make a 2 g/L Rhodium and 9,2 g/L H2SO4.
Do anyone have a clue?
The current draw was the same in both baths and no there was no development of bubbles in the piece. One time I over added the sulfuric and got an darker deposit with bubble development in the cathode.
Here's some pictures:
Left sample is the one I made, and the right one is the one that I bought.