4D Shearforce-Based Constant-Distance Mode Scanning Electrochemical Microscopy

4D shearforce-based constant-distance mode scanning electrochemical microscopy (4D SF/CD-SECM) is designed to assess SECM tip currents at several but constant distances to the sample topography at each point of the x,y-scanning grid. The distance dependent signal is achieved by a shearforce interact...

Full description

Saved in:
Bibliographic Details
Published in:Analytical chemistry (Washington) 2010-09, Vol.82 (18), p.7842-7848
Main Authors: Nebel, Michaela, Eckhard, Kathrin, Erichsen, Thomas, Schulte, Albert, Schuhmann, Wolfgang
Format: Article
Language:English
Subjects:
Analytical chemistry
Chemistry
Diffusion
Electrocatalysis
Electrochemical methods
Electrochemistry - instrumentation
Electrochemistry - methods
Electrodes
Exact sciences and technology
Feasibility Studies
Microelectrodes
Microscopy - instrumentation
Microscopy - methods
Oxidation-Reduction
Platinum - chemistry
Scanning electron microscopy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:4D shearforce-based constant-distance mode scanning electrochemical microscopy (4D SF/CD-SECM) is designed to assess SECM tip currents at several but constant distances to the sample topography at each point of the x,y-scanning grid. The distance dependent signal is achieved by a shearforce interaction between the in-resonance vibrating SECM tip and the sample surface. A 4D SF/CD-SECM measuring cycle at each grid point involves a shearforce controlled SECM tip z-approach to a point of closest distance and subsequent stepwise tip retractions. At the point of closest approach and during the retraction steps, pairs of tip current (I) and position are acquired for various distances above the sample surface. Such a sequence provides x,y,I maps, that can be compiled and displayed for each selected data acquisition distance. Thus, multiple SECM images are obtained at known and constant distances above the sample topography. 4D SF/CD-SECM supports distance-controlled tip operation while continuous scanning of the SECM tip in the shear-force distance is avoided. In this way, constant-distance mode SECM imaging can be performed at user-defined, large tip-to-sample distances. The feasibility and the potential of the proposed 4D SF/CD-SECM imaging is demonstrated using on the one hand amperometric feedback mode imaging of a Pt band electrode array and on the other hand the visualization of the diffusion zone of a redox active species above a microelectrode in a generator/collector arrangement.
ISSN:0003-2700
1520-6882
DOI:10.1021/ac1008805