Understanding gold nanoparticle dissolution in cyanide-containing solution via impact-chemistry

Area of Science:

• Electrochemistry
• Nanotechnology
• Materials Science

Background:

• Gold nanoparticles (AuNPs) have diverse applications.
• Understanding nanoparticle dissolution is crucial for their use and environmental fate.
• Cyanide is a common etchant for gold.

Purpose of the Study:

• To investigate the electrochemical dissolution of citrate-capped gold nanoparticles (AuNPs) in cyanide solutions.
• To compare the dissolution behavior of AuNPs as ensembles versus single particles.
• To determine the conditions for complete oxidation of AuNPs.

Main Methods:

• Electrochemical dissolution experiments.
• Single particle analysis.
• Use of cyanide solutions with varying concentrations.
• Controlled potential application.

Main Results:

• Gold nanoparticles showed distinct dissolution behaviors in bulk versus single-particle studies.
• Complete oxidation of 60 nm AuNPs was achieved at >= 35.0 mM cyanide.
• Oxidation was facilitated at an applied potential of 1.0 V.
• Mechanistic insights and dissolution rate data were obtained.

Conclusions:

• The electrochemical dissolution of AuNPs in cyanide is concentration and potential-dependent.
• Single-particle studies provide detailed insights into nanoparticle reactivity.
• The findings are relevant for applications involving gold nanoparticles in cyanide environments.