Abstract

CARAM, Bruno  and  TUCCERI, Ricardo. Deactivation of nickel hydroxide-gold modified electrodes. Rev. cienc. tecnol. [online]. 2013, n.20, pp.11-18. ISSN 1851-7587.

The aim of the present work was to study how the charge-transport process of a nickel hydroxide film electrochemically synthesized on a gold substrate is modified when the electrode is stored for a long time. It was found that nickel hydroxide films are deactivated under storage, that is, films became less conductive than films immediately prepared (nondeactivated). This study was carried out in the context of the rotating disc electrode voltammetry when the modified electrode contacts an electroactive solution and a mediation reaction occurs at the Au-Ni(OH)₂| electrolyte interface. Variations of anodic limiting currents with the electrode rotation rate, for both nondeactivated and deactivated films in the presence of the electroactive solute deferasirox (4-(3,5-bis(2- hydroxyphenyl)-1,2,4-triazol-1-yl) benzoic acid) allowed the obtention of a charge transport rate across a nickel hydroxide film. This rate decreased with the increase of the storage time.

Keywords : Nickel hydroxide films; Deactivation; Charge transport process; Deferasirox; Mediation reaction.

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