Electrochemical behavior of gold in iodide solutions

P. H. Qi, J Brent Hiskey

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

The electrochemistry of gold in different halide solutions, with special emphasis on iodide is presented. The electrochemical techniques used during this investigation included cyclic and linear sweep voltammetry. A glassy carbon rotating disk electrode was used to investigate the electrochemistry of the iodide and a gold rotating disk electrode to explore the oxidation behavior of gold in iodide solutions. The effects of iodide concentration, electrode rotation and sweep rate on the electrochemical behavior of gold were examined. In addition, reduction of iodine species at the gold electrode was also investigated. Iodide is shown to be a powerful complexing agent for gold. Cyclic voltammograms of gold in the presence of 10-2 M chloride, bromide and iodide, respectively, show that the anodic currents for the oxidation of gold in iodide solution are much greater than that in either bromide or chloride. Two oxidation peaks, which represent the oxidations of Au to Au(I) and to Au(III), were observed. It is confirmed that iodide is oxidized sequentially to tri-iodide and then to iodine and both of these reactions are reversible. At high concentrations of iodide and/or a slow scan rate, passivation, which is caused by the formation of solid iodine at the gold electrode surface, was found. The cathodic reduction curves show that reduction of iodide species on gold is a function of iodine concentrations but it is insensitive to iodide concentration.

Original languageEnglish (US)
Pages (from-to)161-179
Number of pages19
JournalHydrometallurgy
Volume32
Issue number2
DOIs
StatePublished - 1993

Fingerprint

iodide
Iodides
Gold
gold
Iodine
iodine
electrode
Electrodes
Oxidation
electrochemistry
Rotating disks
oxidation
Electrochemistry
Bromides
bromide
Chlorides
chloride
Glassy carbon
Voltammetry
Passivation

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology

Cite this

Electrochemical behavior of gold in iodide solutions. / Qi, P. H.; Hiskey, J Brent.

In: Hydrometallurgy, Vol. 32, No. 2, 1993, p. 161-179.

Research output: Contribution to journalArticle

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