Deactivation of nickel hydroxide-gold modified electrodes.

B. CARAM; R.I. TUCCERI

REVISTA DE CIENCIA Y TECNOLOGíA

CENTRO DE INVESTIGACIÓN Y DESARROLLO TECNOLÓGICO, FACULTAD DE CIENCIAS EXACTAS, QUÍMICAS Y NATURALES, UNIVERSIDAD NACIONAL DE MISIONES

Lugar: Posadas; Año: 2013 vol. 20 p. 11 - 18

0329-8922

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 without use for long time. It was found that nickel hydroxide films deactivate after storage, that is, films become 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 one to obtain the electron charge transport rate across the nickel hydroxide film. The electron charge transport rate decreases with the increase of the storage time.