CETMIC 05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
artículos
Título:
Effect of Oxalate on The Growth of Cuprous Oxide Layers on Copper Electrodes Ellipsometric and Isoelectric Point Study.
Autor/es:
J. O. ZERBINO; R. M.TORRES SANCHEZ; M.G. SUSTERSIC
Revista:
ACTA CHIMICA SLOVENICA
Editorial:
Slovenian Chemical Society
Referencias:
Lugar: Ljubljana,Slovenia; Año: 2009
ISSN:
1318-0207
Resumen:
The effect of the addition of oxalate to the growth of a cuprous oxide layer on copper electrodes was analysed at potential
near that of the open circuit, in borax solutions (7 < pH < 9) by cyclic voltammetry, ellipsometry and surface charge
techniques. The oxide formation is explained as a sequence of Cu2O layer growth, ippl, cationic defect accumulation
and Cu(II) adsorption on the oxide/solution interface, and a dissolution/precipitation step similar to the mechanism previously
reported in oxalate free solutions. The oxalate adsorption at pH = 9 increases the dissolution rate and a greater
thickness of the outer layer, oppl, is obtained. Nevertheless, the oxalate adsorption at pH = 7 decreases the cationic defect
on the cuprous oxide/electrolyte interface, promoting the Cu2O growth. For copper particles immersed in solutions
of pH between 7 and 9, the measured isoelectric point values, iep, (11.8 < iep < 11.5) shifts in the presence of oxalate to
pH between 11.6 and 11.0, respectively. This shift in the iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.2O layer growth, ippl, cationic defect accumulation
and Cu(II) adsorption on the oxide/solution interface, and a dissolution/precipitation step similar to the mechanism previously
reported in oxalate free solutions. The oxalate adsorption at pH = 9 increases the dissolution rate and a greater
thickness of the outer layer, oppl, is obtained. Nevertheless, the oxalate adsorption at pH = 7 decreases the cationic defect
on the cuprous oxide/electrolyte interface, promoting the Cu2O growth. For copper particles immersed in solutions
of pH between 7 and 9, the measured isoelectric point values, iep, (11.8 < iep < 11.5) shifts in the presence of oxalate to
pH between 11.6 and 11.0, respectively. This shift in the iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.oppl, is obtained. Nevertheless, the oxalate adsorption at pH = 7 decreases the cationic defect
on the cuprous oxide/electrolyte interface, promoting the Cu2O growth. For copper particles immersed in solutions
of pH between 7 and 9, the measured isoelectric point values, iep, (11.8 < iep < 11.5) shifts in the presence of oxalate to
pH between 11.6 and 11.0, respectively. This shift in the iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.2O growth. For copper particles immersed in solutions
of pH between 7 and 9, the measured isoelectric point values, iep, (11.8 < iep < 11.5) shifts in the presence of oxalate to
pH between 11.6 and 11.0, respectively. This shift in the iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.iep, (11.8 < iep < 11.5) shifts in the presence of oxalate to
pH between 11.6 and 11.0, respectively. This shift in the iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.iep to a lower pH value indicates oxalate adsorption on the Cu/
Cu2O particles.2O particles.
