Simultaneous Interfacial Reactivity and Topography Mapping with Scanning Ion Conductance Microscopy

Area of Science:

• Electrochemistry
• Surface Science
• Nanotechnology

Background:

• Scanning ion conductance microscopy (SICM) is a versatile technique for imaging material topography.
• Existing SICM methods primarily focus on surface morphology.
• There is a need for techniques that can map dynamic chemical processes at interfaces.

Purpose of the Study:

• To expand the capabilities of SICM for mapping ionic fluxes.
• To demonstrate simultaneous imaging of topography and electrochemical activity.
• To provide a quantitative understanding of interfacial reactions using SICM.

Main Methods:

• Utilizing changes in nanopipet ion conductance to detect local ionic composition variations.
• Employing distance modulation and tuned tip potential for selective imaging.
• Developing simultaneous topography-activity mapping with a single probe.
• Applying finite element method modeling for quantitative analysis.

Main Results:

• SICM successfully mapped spatial distributions of ionic fluxes from electrochemical reactions.
• Simultaneous topography and activity mapping was achieved using tuned bias or distance modulation.
• High-speed imaging captured dynamic electrochemical processes at rates up to 4 frames per second.
• Movies of electrochemical current revealed potential- and time-dependent surface reactivity.

Conclusions:

• SICM is a powerful tool for visualizing and quantifying electrochemical reactions at interfaces.
• The developed methods enable simultaneous mapping of surface topography and reactivity.
• SICM provides valuable spatiotemporal insights into complex electrochemical phenomena.