Investigating Localized Electrochemical of Ferrocenyl-Imidazolium in Ionic Liquid Using Scanning Electrochemical Microscopy Configuration
Abstract
In the present work, the localized electrochemical behavior of redox molecule in ionic liquid
has been investigated using scanning electrochemical microscopy. The electrochemical response of
ferrocenyl-imidazolium redox mediator was studied by recording approach curves over a conducting
and insulating substrate in an undiluted ionic liquid. The SECM approach curve over the conducting
substrate displays a positive feedback, as observed in classical solvent. However, in the case of the
insulating substrate, the approach curve reveals different shapes, depending on the used approach
speed. In this configuration, low approach speed is necessary to reach the expected negative feedback.
Interestingly, at a very close distance between the UME and the insulating substrate, a thin film
behavior is revealed. In addition, the approach curves on both insulator and conducting substrates
can be reconstructed from punctual responses at different distance tip-substrate. The latter match
perfectly with the expected theoretical curves over conducting and insulating under diffusion control.
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