Au(III) ions seem slowly reduced in the presence of silver nanoparticles in a solution containing PVA and water as observed by the color change and visible spectrum. In the absence of silver, no reduction occurs. Thus, can metal silver transfer electrons to gold and undergo oxidation? Thanks.
Gold compounds tend to reduce to metallic gold rather easily especially if organic components are present. Is the colloidal silver suspended in a stabilizing solution of organic salts for example citrate?
the solution contains PVA and AgNPs are capped with citrate. gold is added directly in the solution as Au(III).
Citrate ion is a potential reducing agent for gold salts to metallic gold. That explains your observations.
The standard redox couple Au3+ +3e --> Au is +1.68 V whereas Ag+ + e --> Ag is 0.8V. So in principle Ag (solid) should reduce Au (solution); by applying Nernst equation you can calculate derived potentials for the two couples under different temperature conditions; as far as I see, pH does not matter. Does it make sanse for yoy?
Ciao Matteo
Thanks a lot Fulvio. Yes, I think that both the reducing action of silver and the presence of citrate are reducing gold.
Matteo
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