Electrospun carbon fibers as promising electrodes for enzymatic biofuel cells
Résumé
Enzymatic biofuel cells (BFCs), which can be seen as electrical generators in which enzymes are linked to conductive electrodes, are promising candidates for the production of clean energy from biosourced fuels. Their performances have however not yet allowed bridging the gap between laboratory research and massive industrialization. The limiting points, like short lifetime and poor power density, are directly connected with the BFC electrodes performances. These performances can be improved with better electrode materials, better enzyme-electrode electrical coupling, higher enzyme loading rate and better enzyme stability. An overview of the works performed in our group for the last couple of years will be presented. A mat of electrospun carbon fibers (ECFs) was employed as new electrode. ECFs have interesting properties that meet the demands of BFCs electrodes, like a high specific surface allowing the immobilization of a larger amount of enzymes. In order to enhance properties like electrical conductivity, different nanomaterials, like carbon nanotubes (CNTs), were adsorbed on the surface of the ECFs. The electrodes were then modified by laccase enzyme and employed in the catalytic reduction of oxygen. We observed that current densities increase about 50% for CNT modified electrodes, with values that double those already reported for the laccase enzyme.