Framework of Cytochrome/Vitamin B₂ Linker/Graphene for Robust Microbial Electricity Generation

Area of Science:

• Electrochemistry
• Bioenergy
• Materials Science

Background:

• Bioelectrochemical systems (BES) offer waste-to-energy conversion but suffer from low power density due to poor anodic performance.
• Enhancing anodic efficiency is crucial for practical BES applications.

Purpose of the Study:

• To improve the anodic performance of BES by modifying a glassy carbon electrode with vitamin B2 (VB2) and reduced graphene oxide (rGO).
• To investigate the mechanism of enhanced electron transfer and bioelectricity generation using the VB2/rGO/GC electrode with Geobacter sulfurreducens.

Main Methods:

• Electrodeposition of vitamin B2 onto a reduced graphene oxide-modified glassy carbon electrode (VB2/rGO/GC).
• Electrochemical analysis and molecular simulations to study electron transfer mechanisms.
• Testing the composite electrode in microbial electrolysis cells (MECs).

Main Results:

• The VB2/rGO/GC electrode exhibited 200% higher electrochemical activity compared to a bare GC anode.
• The composite electrode achieved a peak current density of ~210 μA cm⁻² in MECs, with sustained performance.
• VB2 acted as an efficient molecular linker, accelerating electron transfer between microorganisms and the electrode.

Conclusions:

• Vitamin B2 significantly enhances bioelectricity generation and long-term stability in BES.
• The VB2/rGO/GC electrode represents a straightforward and effective strategy for improving bioenergy production.
• This approach facilitates efficient energy conversion between microbial metabolism and artificial electronics.