Copper electrodeposition on Pt(111) in the presence of chloride and (bi)sulfate: Rotating ring-Pt(111) disk electrode studies

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Langmuir

DOI:https://doi.org/10.1021/la00010a075· OSTI ID:136283

Markovic, N M; Gasteiger, H A; Ross, Jr, P N ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

Measurements of the kinetics and the flux of copper ions to an electrode surface by means of a rotating-disk electrode (RRDE) are employed for the first time in a study of the under potential(UPD) and overpotential (OPD) deposition of copper on a Pt(111) disk electrode. The RRD{sub Pt(111)}E measurements presented here show definitively that, in the presence of chloride, Cu UPD is a two-stage process, both of them involving Cu deposition. The coverage of Cu and Cl after the first stage of UPD is ca. 0.58 ML(ML = monolayer). There is little or no additional adsorption of chloride ion during the initial stage of Cu UPD. The second stage of Cu UPD is primarily related to the deposition of Cu forming an essentially complete monolayer (nearly 0.9 ML), accompanied by desorption of approximately 0.1 ML of Cl{sup -}. In pure perchloric acid, Cu electrodeposition is a slow, kinetically controlled process. The presence of either (bi)sulfate and/or chloride in the electrolyte significantly enhances the kinetics of Cu deposition. This enhancement is suggested to be related to the tendency of large anions to perturb the solvation shell of strongly hydrated Cu{sup 2+} ions. In electrolyte with 10{sup -2} M Cl{sup -}, Cu{sup 2+} is partially reduced to Cu{sup +} in the vicinity of the OPD potential region due to its complexation with Cl{sup -}. The observed potential regions of stability for Cu{sup 2+},Cu{sup +}, and Cu{sup 0} were confirmed by a thermodynamic analysis. 36 refs., 11 figs.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 136283
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 10 Vol. 11; ISSN 0743-7463; ISSN LANGD5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ACID SULFATES
CHLORIDES
COPPER IONS
ELECTROCHEMISTRY
ELECTRODEPOSITION
ELECTRODES
KINETICS
PLATINUM
POTENTIALS