The Influence of Metallic Oxides Formed by Repetitive Cyclic Voltammetry or Controlled Potential in the Reactivity of Ir/Hg System

 

E. Milaré, E. Y. Ionashiro, Y. Maniette, A. V. Benedetti and F. L. Fertonani*

Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, C.P. 355, CEP 14.801-970, Brazil

Received 10 September 2002; accepted in revised form 22 November 2002

Abstract

Cyclic voltammetry and controlled potential electrolysis, and other analytical techniques were used to study the reactions of mercury with iridium oxides formed by repetitive cyclic voltammetry (RCV) or by controlled potential electrolysis (CPE) on pure iridium substrate. The oxides were formed in a Hg(I)-containing solution. The SEM images, XPS spectra and CV obtained after the RCV treatment showed a more attacked surface with less mercury on the Ir. On the contrary, the SEM images, XPS spectra and the CV for the electrode prepared by CPE indicated a less attacked surface with more Hg. The oxides formed when the CPE condition was applied inhibited the UPD of mercury.

Keywords: iridium, mercury, cyclic voltammetry.

 

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* Corresponding author. E-mail address: fertonan@iq.unesp.br