PEDOT/PEDOT-S Copolymer-Based Nonaqueous Solid-State Reference Electrode with High Electrochemical and Mechanical...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Nonaqueous electrochemistry demands stable and robust reference electrodes (REs) for accurate potential measurements.
• Traditional Ag/Ag⁺ and Ag/AgCl REs face challenges with contamination and potential drift in nonaqueous solvents.
• Existing polymer-based solid-state reference electrodes (SSREs) often lack structural integrity and exhibit potential instability.

Purpose of the Study:

• To develop a mechanically durable and chemically stable polymer-based SSRE for nonaqueous electroanalytical applications.
• To address the limitations of existing SSREs, including potential drift and ill-defined potentials.

Main Methods:

• Fabrication of a self-doped poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene) sulfonated (PEDOT/PEDOT-S) polymer-based SSRE.
• Electrodeposition of PEDOT/PEDOT-S onto stainless-steel wires with a polytetrafluoroethylene (PTFE) coating.
• Optimization with an internal filling solution (0.1 M TBAPF₆/acetonitrile) and assessment of potential drift over 14 days.

Main Results:

• The fabricated PEDOT/PEDOT-S SSRE demonstrated high mechanical durability and chemical stability.
• Potential drift was significantly reduced, with values of 2.65 μV/h (without inner filling) and 1.72 μV/h (with inner filling) recorded over 14 days.
• The SSRE maintained its function and stability under mechanical stress (bending and twisting) and proved reusable after dry storage.

Conclusions:

• The developed PEDOT/PEDOT-S SSRE offers a robust and stable alternative for nonaqueous electrochemistry.
• Its mechanical integrity, low potential drift, and reusability facilitate practical applications in electroanalysis and electrolysis.
• The potential for prolonged dry storage and easy shipping enhances its utility and accessibility.