Ultrasonic Spray Coating to Optimize Performance of Bio-Electrochemical Systems

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Bio-electrochemical systems (BES) rely on efficient electrode materials for optimal performance.
• Carbon-based electrodes are widely used but can be further enhanced for improved electrochemical activity.
• Nanostructured coatings offer a pathway to increase electrode surface area and functionality.

Purpose of the Study:

• To investigate the use of ultrasonic spray coating (USC) for depositing poly(3,4-ethylene-dioxy-thiophene) poly(styrene-sulfonate) (PEDOT:PSS) on carbon paper electrodes.
• To evaluate the impact of PEDOT:PSS nanocoatings on the electrochemical properties of carbon electrodes.
• To assess the performance enhancement of microbial fuel cells (MFCs) utilizing these modified electrodes.

Main Methods:

• Fabrication of carbon electrodes coated with PEDOT:PSS using ultrasonic spray coating (USC).
• Morphological and spatial uniformity analysis using scanning electron microscopy (SEM) and Raman spectroscopy.
• Electrochemical characterization to determine the electrochemical active surface area (ECSA).
• Performance testing of modified electrodes in a lab-scale microbial fuel cell (MFC) experiment.

Main Results:

• USC enabled uniform and controlled deposition of PEDOT:PSS nanostructured layers on carbon paper.
• Electrodes modified with PEDOT:PSS showed a more than two-fold increase in electrochemical active surface area.
• Microbial fuel cells (MFCs) with USC-deposited PEDOT:PSS electrodes exhibited a three-fold higher energy recovery, reaching (13 ± 2) J·m^-3.
• The quantity of PEDOT:PSS used was comparable to literature values for other deposition techniques.

Conclusions:

• Ultrasonic spray coating (USC) is a viable and effective method for applying PEDOT:PSS nanocoatings to carbon electrodes.
• PEDOT:PSS modification significantly enhances the electrochemical performance of carbon electrodes for BES applications.
• USC presents a promising technique for the scalable fabrication of improved electrodes for bio-electrochemical systems, particularly microbial fuel cells.