Authors: M Bougouma A Van Elewyck M Steichen C BuessHerman Th Doneux
Publish Date: 2012/11/30
Volume: 17, Issue: 2, Pages: 527-536
Abstract
The electrochemical behaviour of selenium in the deep eutectic solvent made of a 12 molar ratio of choline chloride and urea ChCl–U has been investigated at a polycrystalline gold electrode by voltammetry and chronoamperometry In order to favour the deposition of grey selenium selenium oxide was chosen as the solution precursor and a temperature range from 70 to 110 °C was selected Cyclic voltammograms recorded in the 12 choline chloride–urea liquid containing 10 mM SeO2 are strongly affected by the temperature At 110 °C three main cathodic responses are evidenced around −0075 −02 and −07 V These cathodic peaks have been attributed respectively to the underpotential deposition upd of Se the bulk deposition of Se and the cathodic stripping of selenium associated to the formation of Se−II Potentiostatic current transients obtained at 110 °C are indicative of a nucleation with diffusioncontrolled growth mechanism for the selenium electrodeposition and support the formation of a upd layer preceding the bulk deposition The dissolution transients triggered by double potential step perturbations could however not be interpreted on the basis of a similar formalism
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