Dual layered CNT structure air cathode for power generation from microbial fuel cells

Abstract

A new cathode, layered with hydrophilic and hydrophobic structures using multiwall carbon nanotubes treated with nitric acid, was developed. The performance of the new cathode for the production of power from a microbial fuel cell was tested and compared to a commercial carbon cloth cathode, with Platinum as a catalyst, for the reduction of oxygen. The maximum power density of a hydrophobic layered only CNT (Carbon Nanotube) cathode, using a polytetrafluroethylene binder, was as low as 81-85 mW/m(2), which was only 58.2% that of the MFC (Microbial Fuel Cell) with the graphite cloth cathode containing Pt. The performance of the MFC with the cathode was also limited by the reduction of oxygen. The cathodic potential obtained from the MFC installed with hydrophilic (Nafion binder) and hydrophobic (PTFE binder) dual layered CNT cathodes, using MWCNT (Multiwall Carbon Nanotube) pretreated with nitric, acid was reasonably high, and its maximum power density was 40% higher than that of the MFC with a commercial graphite cloth containing Pt for the reduction of oxygen.