Electrochemical behavior of copper metal core/oxide shell ultra-fine particles on mercury electrodes in aqueous dispersions

Andrey Korshunov, Michael Heyrovský

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Methods of voltammetry and polarography have been applied to study electrochemical behavior of ultrafine copper particles with Z-average diameter ∼120 nm in aqueous electrolytic media on mercury electrodes. Particles have been preliminarily stabilized by controllable passivation at low partial pressures of oxygen what resulted in formation of superficial oxide shell with certain composition and structure. It has been found that special electrochemical behavior of the particles in aqueous media is caused by the size effects as well as by the processes (partial dissolution, complexation) occurring at the "particle/solution" interface. Electroreduction of the dispersions takes place at about -0.8 V (Ag/AgCl/KCl sat.). The mechanism of electroreduction includes an adsorption stage due to electric charge which the particles bear in the electrolyte. The particle adsorption on the electrode has been shown by differential capacity measurements, the surface charge in different electrolytes was estimated by means of potentiometric titration of the dispersions. The sign of the charge and the probable electroactive species formed by partial dissolution of CuO and Cu2O in the electrolytic medium have been considered on basis of equilibria at the copper particle/dispersion interface.

Original languageEnglish
Pages (from-to)23-29
Number of pages7
JournalJournal of Electroanalytical Chemistry
Volume629
Issue number1-2
DOIs
Publication statusPublished - 15 Apr 2009

Fingerprint

Mercury (metal)
Mercury
Dispersions
Oxides
Electrolytes
Copper
Dissolution
Metals
Shells (structures)
Polarographic analysis
Adsorption
Electrodes
Electric charge
Voltammetry
Surface charge
Complexation
Titration
Passivation
Partial pressure
Oxygen

Keywords

  • Aqueous dispersions
  • Hg electrodes
  • Surface oxide layers
  • Ultrafine copper powders
  • Voltammetry

ASJC Scopus subject areas

  • Analytical Chemistry
  • Chemical Engineering(all)
  • Electrochemistry

Cite this

Electrochemical behavior of copper metal core/oxide shell ultra-fine particles on mercury electrodes in aqueous dispersions. / Korshunov, Andrey; Heyrovský, Michael.

In: Journal of Electroanalytical Chemistry, Vol. 629, No. 1-2, 15.04.2009, p. 23-29.

Research output: Contribution to journalArticle

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