Biohybrid Cathode in Single Chamber Microbial Fuel Cell.

Area of Science:

• Electrochemistry
• Microbiology
• Materials Science

Background:

• Microbial fuel cells (MFCs) utilize biofilms for energy conversion.
• Cathode electrodes are critical for oxygen reduction reaction (ORR) in MFCs.
• Biofilms can act as biocatalysts for ORR, but their performance varies.

Purpose of the Study:

• To investigate the catalytic properties of biofilms grown on cathode electrodes for ORR.
• To compare the performance of Pt-based biohybrid cathodes with Pt-free biocathodes.
• To analyze the electrochemical properties of cathodic biofilms.

Main Methods:

• Single-chamber microbial fuel cells (MFCs) were constructed with different cathode materials.
• Biofilms were allowed to spontaneously grow on carbon-based cathode electrodes.
• Linear sweep voltammetry (LSV) was used to characterize ORR performance.
• Electrochemical impedance spectroscopy (EIS) was employed to analyze biofilm properties.

Main Results:

• Biofilms enhanced ORR performance on both Pt-based and Pt-free cathodes compared to biofilm-free controls.
• Pt-based biohybrid cathodes, incorporating biofilms and Pt/C, exhibited superior performance.
• Electrochemical impedance spectroscopy revealed specific properties of the cathodic biofilms.

Conclusions:

• Spontaneously grown aerobic biofilms enhance ORR catalysis in MFCs.
• Biohybrid cathodes combining biofilms with platinum demonstrate synergistic catalytic activity.
• Optimized biofilm-cathode interactions are crucial for maximizing power production in MFCs.