Authors: M O Solaliendres A Manzoli G R SalazarBanda K I B Eguiluz S T Tanimoto S A S Machado
Publish Date: 2007/09/06
Volume: 12, Issue: 6, Pages: 679-686
Abstract
The processes involved in the Se electrodeposition mainly the one related to the formation of H2Se species on Au electrode in perchloric acid solutions have been investigated through cyclic voltammetry electrochemical quartz crystal microbalance EQCM rotating ringdisc electrode RRDE and atomic force microscopy AFM techniques In the experiments performed with the EQCM with the potential sweep in the negative direction the responses for the mass variation were divided in three welldefined potential regions A from 155 to 035 V B from 035 to −037 V and C from −037 to −049 V It was verified that the following processes can occur respectively the species AuO2H2SeO3 was desorbed during the AuO reduction the reduction of SeIV to Se0 and the formation of H2Se When the potential was swept in the positive direction the responses for the mass variation were divided in four welldefined potential regions D from −049 to 066 V E from 066 to 099 V F from 099 to 126 V and G from 126 to 155 V and the described processes in these regions were respectively the Se deposition and adsorption of water molecules and/or perchlorate ions the Se dissolution the Se incorporating mass in the form of HO–Se and the Au oxidation all potentials are referred to the Ag/AgCl electrode Making use of the RRDE using the collection technique the formation of H2Se species during the Se electrodeposition was investigated Therefore it was confirmed that this species is formed on the disc electrode between −03 and −055 V vs the Ag/AgCl potential range collecting the oxidized compound onto the ring electrode AFM images also indicated that the surface topography of the Semassive deposit on Au is different from the images registered after the formation of H2Se species confirming the cathodic stripping of Se
Keywords: