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Carbon electrodes for direct electron transfer type laccase cathodes investigated by current density-cathode
Stefanie Rubenwolf1, Oliver Strohmeier, Arne Kloke
1Laboratory for MEMS Applications, Department of Microsystems Engineering-IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany. stefanie.rubenwolf@imtek.uni-freiburg.de
Biosensors & Bioelectronics
|July 15, 2010
Summary
This study compares carbon electrode materials for enzymatic biofuel cells. Laccase adsorption enhances performance, with carbon nanofibers and multi-walled carbon nanotubes showing the best results.
Area of Science:
- Bioelectrochemistry
- Enzyme catalysis
- Renewable energy
Background:
- Mediatorless enzymatic biofuel cells utilize direct electron transfer from carbon electrodes to laccase.
- Current data on oxygen reduction performance across different carbon materials is poorly comparable.
- Standardized characterization is needed for optimizing biofuel cell cathode design.
Purpose of the Study:
- To comparatively characterize various carbon-based electrode materials for laccase-based oxygen reduction.
- To evaluate the impact of laccase adsorption on electrode performance.
- To identify optimal carbon materials for enzymatic biofuel cell cathodes.
Main Methods:
- Comparative half-cell analysis of carbon electrode materials (nanotubes, carbon nanofibers, multi-walled carbon nanotubes, graphite felt, porous carbon tubes).
- Adsorption of Trametes versicolor laccase onto electrode surfaces.
- Measurement of open circuit potentials and current densities at a fixed potential (0.5 V vs. SCE).
- Normalization of performance data by electrode volume and BET surface area.
Main Results:
- Laccase adsorption significantly increased open circuit potentials and overall performance, confirming direct electron transfer.
- Volume-normalized current densities varied, with carbon nanofibers and multi-walled carbon nanotubes showing higher performance (70 and 77 μA cm⁻³).
- Carbon nanotubes and porous carbon tubes exhibited lower current densities when normalized by surface area compared to graphite felt and carbon nanofibers.
Conclusions:
- Carbon electrode material choice significantly impacts laccase-based oxygen reduction performance in enzymatic biofuel cells.
- Carbon nanofibers and multi-walled carbon nanotubes are promising materials for cathode development.
- Further research is needed to understand enzyme-electrode interactions and optimize nanotube dispersion for enhanced performance.
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