Kinetic study of silver (I) oxide layer electroreduction

Abstract

The potentiostatic electroreduction of silver(I) oxide layer has been investigated in 0.1 M NaOH. The study was complemented by electroreduced silver surface characterisation through scanning electron microscopy micrographs and thallium UPD voltammetry. By properly adjusting the electroreduction conditions three well-defined processes could be distinguished: (i) the electroreduction of the Ag2O monolayer in direct contact with the silver substrate which involves a current decay following a first order law; (ii) the electroreduction of the primary Ag2O layer which can be described through an instantaneous nucleation and 3-D growth mechanism under diffusion control; (iii) the electroreduction of the secondary Ag2O layer involving a nucleation and 3-D conical growth under charge transfer control and a correction term for the death of growing nuclei. SEM and thallium UPD results correlate, in principle, with the conclusions derived from the electrochemical data.