Noncontact electrochemical imaging with combined scanning electrochemical atomic force microscopy

Area of Science:

• Surface science
• Analytical chemistry
• Materials science

Background:

• Scanning electrochemical atomic force microscopy (SECM-AFM) integrates topographical and electrochemical imaging.
• Existing SECM-AFM techniques require further development for noncontact electrochemical analysis.

Purpose of the Study:

• To develop and demonstrate novel noncontact amperometric imaging strategies for SECM-AFM.
• To enable simultaneous acquisition of high-resolution surface topography and electrochemical data.
• To investigate solid-liquid interfaces with enhanced correlation between morphology and electrochemical activity.

Main Methods:

• Development of two noncontact amperometric imaging strategies for SECM-AFM.
• Contact mode AFM for topographical imaging.
• Noncontact amperometric imaging with tip retraction or Lift Mode.
• SECM feedback and substrate generation-tip collection measurements using a Pt disk UME.

Main Results:

• Demonstrated successful implementation of two noncontact amperometric imaging strategies.
• Achieved close correlation between electrochemical images and underlying surface topography.
• Validated the technique using a 10-microm-diameter Pt disk UME as a model substrate.

Conclusions:

• The developed noncontact SECM-AFM strategies significantly extend the capabilities of scanned probe microscopy.
• These methods allow for precise correlation of electrochemical information with detailed surface morphology.
• The technique offers a powerful tool for investigating solid-liquid interfaces in various scientific disciplines.