Carbon nanotube as an alternative cathode support and catalyst for microbial fuel cells

Microbial fuel cells (MFCs) hold great promise as an alternative for direct biochemical energy extraction from both biomass and wastewater. However, the commercialization and scaling-up of MFCs is not completely feasible, due to the high price of platinum (Pt) as a cathode catalyst. In this paper, we studied the use of a carbon nanotube (CNT) composite catalyst, to reduce the amount of Pt (without decline of efficiency) for moving towards the commercialization of MFCs. CNT/Pt composite electrodes would increase MFC power output by 8.7–32.2%; with respect to the pristine Pt as a catalyst for the cathode at a chemical oxygen demand (COD) substrate of 100 mg/l and 2000 mg/l, respectively. Moreover, the amount of Pt in the CNT/Pt electrode could be reduced by up to 25% of the amount necessary for a conventional Pt/carbon electrode.