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Spatial Imaging of Cu 2+ ‐Ion Release by Combining Alternating Current and Underpotential Stripping Mode Scanning Electrochemical Microscopy
Author(s) -
Ruhlig Dirk,
Schuhmann Wolfgang
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603693
Subject(s) - scanning electrochemical microscopy , underpotential deposition , copper , chemistry , cyclic voltammetry , analytical chemistry (journal) , voltammetry , microelectrode , electrochemistry , stripping (fiber) , anodic stripping voltammetry , inorganic chemistry , materials science , electrode , chromatography , organic chemistry , composite material
Anodic underpotential stripping voltammetry was integrated into SECM in order to characterize local corrosion of metallic copper deposits on metal surfaces as a model for copper containing alloys. Primarily, the alternating current mode of SECM was applied in an electrolyte of low ionic strength for localizing possible corrosion sites without any perturbation of the corroding surface, e.g., by the presence of any redox mediator. Sequentially, the release of Cu 2+ ‐ions was confirmed and locally visualized at the previously detected electrochemically active sites by means of spatially resolved anodic underpotential stripping voltammetry performed during SECM scanning. Underpotential stripping voltammetry of Cu 2+ ‐ions was performed at a specifically developed 15 μm gold‐coated Pt microelectrode used as SECM tip with a detection limit of 0.15 nM Cu 2+ ( N =4, RSD =6%) for an accumulation of 45 s at −0.4 V. SECM images of model samples such as copper coated microelectrodes and lacquered metallic copper workpieces demonstrated the feasibility and applicability of combining AC‐ and underpotential stripping mode of SECM for local visualization of Cu 2+ ‐ion release from corroding surfaces.