A Dual-Barrel Carbon Fiber Microelectrode for Generator-Collector Experiments

Area of Science:

• Electrochemistry
• Materials Science

Background:

• Generator-collector systems are crucial for electrochemical studies, including kinetics and quantification.
• Microelectrodes offer advantages like well-defined diffusion profiles for precise measurements.

Purpose of the Study:

• To describe a novel protocol for fabricating a dual carbon fiber microelectrode.
• To evaluate the microelectrode's performance in generator-collector and scanning electrochemical microscopy (SECM) configurations.
• To demonstrate the microelectrode's utility for analytical quantification.

Main Methods:

• Fabrication of a dual carbon fiber microelectrode using a dual-barrel capillary and inexpensive carbon fiber.
• Electrochemical characterization and scanning electron microscopy (SEM) imaging of the microelectrode.
• Application in generator-collector mode with a redox probe ([Ru(NH3)6]3+) and in SECM for analyzing the iodide/iodine system.

Main Results:

• The fabricated microelectrodes possess a microdisc geometry with well-defined diffusion.
• An increase in collection efficiency was observed during approach to an insulating substrate in SECM.
• Analytical information was obtained by correlating collection efficiency with thiosulfate concentration in the iodide/iodine system.

Conclusions:

• A cost-effective and straightforward method for fabricating dual carbon fiber microelectrodes was established.
• The microelectrode is suitable for generator-collector and SECM applications, demonstrating effective redox probe collection.
• The device shows potential for quantitative analytical measurements in electrochemical systems.