The anodic behavior of silver in chloride solutions—I. The formation and reduction of thin silver chloride films

✍ Scribed by V.I. Birss; C.K. Smith

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 988 KB
• Volume: 32
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(87)85033-8

✦ Synopsis

The initial stages of growth and the subsequent reduction of A&l films at a silver electrode in aqueous chloride solutions has been investigated using potentiodynamic and potentiostatic methods. The first step in the growth process involves the two-dimensional deposition of either a partial monolayer (5&75 nC cm-') of AgCl film or the adsorption of chloride ions involving a partial charge transfer. Following this, at an overpotential of typically 2&40 mV, the nucleation and growth of three-dimensional AgCl films commences. Reduction of this type of AgCl film is characterized by two cathodic peaks,possibly depicting the reduction of AgCl nuclei formed by two nucleation mechanisms. Continuous potential cycling results in significant increases in the nucleation currents and charges (not due to conventional electrode roughening), indicating that active silver nuclei are being left on the electrode sufrace upon AgCl film reduction. However, by maintaining the potential at a value significantly negative of AgCl film growth for a period of time, the currents due to the three-dimensional nucleation and growth process diminish in magnitude. This is evidence for an active reconstruction of the silver surface leading to the loss of these silver nuclei.