High-power "nesting-doll" biofuel cell enabled by free-standing electrodes with inherent enzymatic function

Area of Science:

• Electrochemistry
• Green Energy Technology
• Materials Science

Background:

• Biofuel cells (BFCs) offer a promising avenue for green energy generation through biocatalyst-mediated redox reactions.
• However, their practical application is hindered by suboptimal performance and stability issues, often linked to enzyme-electrode interface limitations.

Purpose of the Study:

• To develop a novel, all-in-one strategy for fabricating free-standing electrodes with inherent enzyme-like activity and high conductivity.
• To eliminate dynamic limitations at the enzyme-electrode interface for enhanced electron transfer and BFC stability.
• To create a high-performance, stable biofuel cell by integrating these advanced electrode designs.

Main Methods:

• Fabrication of a free-standing cathode with laccase-like activity on copper foam via "ionic corrosion-electrografting coordination".
• In-situ loading of gold nanoparticles on nickel foam to mimic glucose oxidase activity for the anode.
• Development of a "nesting doll" nanozyme BFC with a multi-shell coaxial configuration, placing the anode inside the cathode.

Main Results:

• The developed electrodes exhibited inherent enzyme-like activity and high conductivity, eliminating the need for enzyme coatings and facilitating rapid electron transfer.
• The nanozyme BFC achieved a high open-circuit voltage of 1.7 V.
• An impressive output power density of 3639.0 μW cm⁻² was recorded, surpassing previously reported literature values.

Conclusions:

• The proposed strategy effectively enhances the output performance and stability of biofuel cells.
• This pioneering approach broadens the potential applications of BFCs in the field of sustainable energy.
• The enzyme-mimicking electrodes and novel device architecture represent a significant advancement in BFC technology.