Scanning electrochemical microscopy with conducting polymer probes: Validation and applications

Claudio-Cintron, Marie Angellie

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https://hdl.handle.net/2142/101821 Copy

Description

Title

Scanning electrochemical microscopy with conducting polymer probes: Validation and applications

Author(s)

Claudio-Cintron, Marie Angellie

Issue Date

2018-07-13

Director of Research (if dissertation) or Advisor (if thesis)

Rodríguez-López, Joaquín

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

conducting polymers, electrochemistry, scanning electrochemical microscopy

Abstract

Scanning electrochemical microscopy (SECM) is a useful technique for exploring redox and ionic processes on active materials. Here we explore how conducting polymers (CPs) offer several advantages as probe electrode material, given its versatility in the measurement of redox and ionic processes, resulting in a probe that can simultaneously respond to these two aspects. Our CP probes can be modified and fine-tuned to improve experimental parameters and they can be easily prepared by electrodeposition. In this paper, we show a new type of CP probe for SECM that retains the spatial resolution of conventional metal probes and introducing the possibility to exploit their properties to study a wider range of systems. To demonstrate the usefulness of the probe, an insulating substrate with conducting features was imaged with a Pt electrode, a film-coated electrode and a CP well-probe electrode. Sharp contrast was observed for both the CP well-probe and the Pt probe, proving the efficiency of the new electrode. Additionally, an organosulfur compound was used as mediator taking advantage of the electrocatalytic effect PEDOT and its resistance to fouling from S-derived species. Finally, these probes were also applied for ionic imaging in the absence of a redox mediator, taking advantage of the polymer charging current to assess the local electrochemical environment of the probe. The anion size was investigated for its influence in the detection of small concentration changes due to proximity to an insulating substrate. Conducting polymers were successfully employed as electrode materials for SECM probes, expanding the potential of this instrumental technique to unique mediators and systems.

Graduation Semester

2018-08

Type of Resource

text

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http://hdl.handle.net/2142/101821

Copyright and License Information

Copyright 2018 Marie Claudio-Cintron

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