Electric-Double-Layer-Modulation Microscopy

Abstract

The electric double layer (EDL) formed around charged nanostructures at the liquid-solid interface determines their electrochemical activity and influences their electrical and optical polarizability. We experimentally demonstrate that restructuring of the EDL at the nanoscale can be detected by dark-field scattering microscopy. Temporal and spatial characterization of the scattering signal demonstrates that the potentiodynamic optical contrast is proportional to the accumulated charge of polarisable ions at the interface and its time derivative represents the nanoscale ionic current. The material-specificity of the EDL formation is used in our work as a label-free contrast mechanism to image nanostructures and perform spatially-resolved cyclic voltametry on ion current density of a few attoamperes, corresponding to the exchange of only a few hundred ions.

arXiv comment6 pages, 4 figrues

References in corpus (1)

• Diffuse-Charge Dynamics in Electrochemical Systems

Cited by in corpus (5)

• Operando optical tracking of single-particle ion dynamics and phase transitions in battery electrodes
• Emerging Optical Microscopy Techniques for Electrochemistry
• Electrochemistry and Optical Microscopy
• Operando Label-free Optical Imaging of Solution-Phase Ion Transport and Electrochemistry
• Computing the Local Ion Concentration Variations for Electric-Double-Layer-Modulation Microscopy