Air diffusion biocathode with CueO as electrocatalyst adsorbed on carbon particle-modified electrodes

Area of Science:

• Electrochemistry
• Biocatalysis
• Biofuel Cells

Background:

• Biofuel cell performance is often limited by the low solubility and diffusion of dissolved oxygen (O2) in electrolyte solutions.
• Efficient oxygen reduction is crucial for enhancing the power output of biocathodes.

Purpose of the Study:

• To engineer an air-diffusion biocathode for biofuel cells to overcome oxygen mass transport limitations.
• To improve the current density of oxygen reduction by utilizing atmospheric O2 directly.

Main Methods:

• Constructed an air-diffusion biocathode using CueO from Escherichia coli as the cathodic biocatalyst.
• Immobilized CueO onto Ketjen black-modified carbon paper electrodes with optimized polytetrafluoroethylene binder content for hydrophobicity.
• Investigated oxygen reduction catalyzed by CueO on the modified electrode surface.

Main Results:

• Achieved high current densities for oxygen reduction, reaching up to 20 mA cm(-2) at 0 V vs. Ag|AgCl.
• Demonstrated the effectiveness of the air-diffusion biocathode in enhancing oxygen supply and utilization.
• The hydrophobic electrode surface facilitated efficient O2 access to the biocatalyst.

Conclusions:

• The developed air-diffusion biocathode effectively overcomes oxygen supply limitations in biofuel cells.
• Utilizing atmospheric oxygen directly with CueO as a biocatalyst significantly enhances current density.
• This approach offers a promising strategy for advancing biofuel cell technology.