College of Arts and Sciences Publications and Scholarship
Abstract
We have developed a new imaging method for SECM employing fast scan anodic stripping voltammetry (ASV) to provide sensitive and selective imaging of multiple chemical species at interfaces immersed in solution. A rapid CV scan (100 V/s) is used along with a short preconcentration time (300-750 ms) to allow images to be acquired in a normal SECM time frame. A Hg-Pt film electrode is developed having an equivalent Hg thickness of 40 nm that has good sensitivity at short preconcentration times and also retains thin-film behavior with high-speed voltammetric stripping. Fast scan anodic stripping currents are shown to be linear for 1-100 mM of Pb2+ and Cd2+ solutions using a preconcentration time of 300 ms. SECM images showing the presence of Pb2+ and Cd2+ at concentrations as low as 1 mM are presented. In addition, a single ASV-SECM image is shown to produce unique concentration maps indicating Cd2+ and Pb2+, generated in situ from a corroding sample, while simultaneously detecting the depletion of O2 at this sample. The transient voltammetric response at the film electrode is simulated and shows good agreement with the experimental behavior. We discuss the behavior of images and concentration profiles obtained with different imaging conditions and show that mass- transport limitations in the tip-substrate gap can induce dissolution. ASV-SECM can thus be used to detect and study induced dissolution not only at bulk metal surfaces but also on UPD layers, in this case Cd and Pb on Pt. In addition, we discuss how surface diffusion phenomena may relate to the observed ASV-SECM behavior.
Publisher
Analytical Chemistry
First Page
3612
Last Page
3621
Publication Date
2008
College
College of Arts and Sciences
Department
Department of Chemistry
Disciplines
Analytical Chemistry | Materials Chemistry
Recommended Citation
Alpuche-Aviles, Mario A.; Baur, John E.; and Wipf, David O., "Imaging of Metal Ion Dissolution and Electrodeposition by Anodic Stripping Voltammetry – Scanning Electrochemical Microscopy" (2008). College of Arts and Sciences Publications and Scholarship. 31.
https://scholarsjunction.msstate.edu/cas-publications/31
Comments
"This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Analytical Chemistry, copyright © 2008 American Chemical Society after peer review. To access the final edited and published work see
Alpuche-Aviles MA, Baur JE, Wipf DO. Imaging of metal ion dissolution and electrodeposition by anodic stripping voltammetry-scanning electrochemical microscopy. Anal Chem. 2008 May 15;80(10):3612-21.
http://dx.doi.org/10.1021/ac702568c