Na2S2O3 as a gold precipitant?

[eugene-bright]

The paper mentions traditional one-step reduction of HAuCl4 by sodium thiosulfate.

The quoted paper mentions the reduction of metallic gold by thiosulfate in the diluted solutions. I tried to give it a try by replacing MBS with thiosulfate. I leant the lesson.
To the topic started and other seekers: no luck here unless you are working with pure diluted solutions in the field of gold nanoparticle synthesis.

 

[Yggdrasil]

The quoted paper mentions the reduction of metallic gold by thiosulfate in the diluted solutions. I tried to give it a try by replacing MBS with thiosulfate. I leant the lesson.
To the topic started and other seekers: no luck here unless you are working with pure diluted solutions in the field of gold nanoparticle synthesis.

I guess you meant SMB not MBS?

 

[eugene-bright]

I guess you meant SMB not MBS?

I meant metabisulfites in general, SMB is the most available, yeah.

 

[Yggdrasil]

I meant metabisulfites in general, SMB is the most available, yeah.

Any Sulfite will do but SMB is most effective.

 

[orvi]

Sodium thiosulfate is very unplesant chemical to work with - altough it is nontoxic (generally speaking). In acidic enviroment, it decomposes into elemental sulfur and other sulfur compounds - that is the "red" colour.

Use any type of sulfite or metabisulfite (or straight SO2 gas). Potassium or sodium ones. Or cement on copper.
SMB is most economical one from 4 available. But others work equally well.
If your gold don´t drop there are two possibilities - there isn´t enough gold to show up, or you have excess oxidizer in the mixture.

 

[eugene-bright]

In this crazy video I observe strong anodic reaction, though I expected the gold being recovered on the cathode. It looks more like that the gold is being reduced by the anode material itself, otherwise it doesn't make sense for me.

It's an off topic but as I've brought it here already anyway... I've got an intuition on how that electrolysis trick works. Iron anode dissolution provides Fe2+ which in turn reduce the gold.

 

[Yggdrasil]

It's an off topic but as I've brought it here already anyway... I've got an intuition on how that electrolysis trick works. Iron anode dissolution provides Fe2+ which in turn reduce the gold.

Iron alone will cement it.

 

[eugene-bright]

Iron alone will cement it.

Right. But in the video the reaction goes in the volume and unexpectedly vigorously.
Anyway it's an off topic.