Scanning Electrochemical Cell Microscopy (SECCM) Chronopotentiometry: Development and Applications in Electroanalysis
Enrico Daviddi1, Katerina L Gonos1, Alex W Colburn1
1Department of Chemistry , University of Warwick , Coventry CV4 7AL , U.K.
Analytical Chemistry
|June 29, 2019
Summary
This study introduces controlled-current scanning electrochemical cell microscopy (SECCM) for nanoscale mapping of electrochemical activity and surface topography. The technique successfully characterized electron transfer and hydrogen evolution reactions, showing enhanced activity at electrode edges.
Area of Science:
- Electrochemistry
- Nanotechnology
- Materials Science
Background:
- Scanning electrochemical cell microscopy (SECCM) is typically used in controlled-potential modes for nanoscale (electro)activity mapping.
- Controlled-current (galvanostatic/chronopotentiometric) SECCM has not been extensively explored for simultaneous electrochemical activity and topographical mapping.
Purpose of the Study:
- To develop and validate controlled-current SECCM for nanoscale electrochemical analysis.
- To investigate electrochemical systems including electron transfer and electrocatalysis using this new mode.
Main Methods:
- Utilized scanning electrochemical cell microscopy (SECCM) in a controlled-current (chronopotentiometric) mode.
- Applied the technique to study the [Ru(NH3)6]3+/2+ redox process on glassy carbon and aged highly ordered pyrolytic graphite (HOPG).
- Benchmarked the hydrogen evolution reaction (HER) on molybdenum disulfide (MoS2) using chronopotentiometric SECCM.
Main Results:
- Demonstrated synchronous acquisition of spatially resolved electrode potential and topographical data.
- Observed enhanced electrochemical activity at the edge plane versus basal plane for both the Ru complex and MoS2 HER electrocatalysis.
- Experimental data aligned well with theoretical predictions and previous controlled-potential SECCM studies.
Conclusions:
- Controlled-current SECCM is a viable technique for quantitative nanoscale electroanalysis.
- The method provides new possibilities for studying energy storage, electrocatalyst benchmarking, and corrosion.
- Edge planes of materials like HOPG and MoS2 exhibit distinct electrochemical properties compared to basal planes.
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