Three-dimensional carbon nanofiber-based anode for high generated current and power from air-cathode micro-sized MFC

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Microbial fuel cells (MFCs) face limitations in power density due to poor mass transfer and reaction kinetics.
• Microscale MFCs offer a solution for mass transfer issues, but reaction kinetics remain a bottleneck.
• Electrode properties like size, shape, and material critically influence MFC reaction kinetics.

Purpose of the Study:

• To introduce a 3D carbon nanofiber disk as an improved anode for microscale MFCs.
• To enhance reaction kinetics and power density in single-chamber air-cathode MFCs.
• To investigate the effect of electrospinning time on anode performance.

Main Methods:

• Fabrication of a 3D carbon nanofiber disk anode using electrospinning and thermal treatment.
• Integration of the fabricated anode into a single-chamber air-cathode micro-sized MFC.
• Optimization of the carbon nanofiber layer thickness by adjusting electrospinning duration.

Main Results:

• The 3D carbon nanofiber anode improved reaction kinetics in the micro-sized MFC.
• High power density (8.1 Wm⁻²) and current density (44.9 Am⁻²) were achieved in a 19.6 μL MFC.
• Anode fabricated with 10 min electrospinning time showed 1.5x and 2x higher power density than 5 min and 20 min ones, respectively.

Conclusions:

• 3D carbon nanofiber disks are effective anodes for enhancing microscale MFC performance.
• Optimizing electrospinning time is crucial for maximizing power output.
• This electrode design offers a promising pathway for advancing MFC technology.