Design of Carbon Nanotube-Based Gas-Diffusion Cathode for O2 Reduction by Multicopper Oxidases (Postprint)
Abstract
Multicopper oxidases, such as laccase or bilirubin oxidase, are known to reduce molecular oxygen at very high redox potentials, which makes them attractive biocatalysts for enzymatic cathodes in biological fuel cells. By designing an enzymatic gas-diffusion electrode, molecular oxygen can be supplied through the gaseous phase, avoiding solubility and diffusion limitations typically associated with liquid electrolytes. In doing so, the current density of enzymatic cathodes can theoretically be enhanced. This publication presents a material study of carbon/Teflon composites that aim to optimize the functionality of the gas-diffusion and catalytic layers for application in enzymatic systems. The modifi cation of the catalytic layer with multiwalled carbon nanotubes, for example, creates the basis for stronger pi - pi stacking interactions through tethered enzymatic linkers, such as pyrenes or perylene derivates. Cyclic voltammograms show the effective direct electron contact of laccase with carbon nanotube-modifi ed electrodes via tethered crosslinking molecules as a model system. The polarization behavior of laccase-modified gas-diffusion electrodes reveals open-circuit potentials of + 550 mV (versus Ag/AgCl) and current densities approaching 0.5 mA cm 2 (at zero potential) in air-breathing mode.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 04, 2011
- Accession Number
- ADA590556
Entities
People
- Carolin Lau
- Emily R. Adkins
- Glenn R. Johnson
- Heather R. Luckarift
- Plamen Atanassov
- Ramaraja P. Ramasamy
Organizations
- University of New Mexico