Study on Membranes and Cathode Catalysts in Microbial Fuel Cells

Abstract

Microbial fuel cell (MFC) is a device harnessing microorganisms to harvest biomass energy from wastewater. It shows great promise because of its ability for simultaneous energy recovery and wastewater treatment. However, it is still in its infancy with materials to be optimized. In this study, we have focused on membrane and cathode catalyst in MFCs.

In the first part (Chapter 2), nanoporous membranes are examined as separators to substitute ion exchange membrane. Polyethersulfone membrane-based MFC yielded the highest power, 92% comparing with that based on cation exchange membrane. From a general point of view, polyethersulfone membrane could be a cheaper and durable alternative as MFC separators.

In the second part (Chapter 3-5), cathode catalysts in microbial fuel cells were studied. Several noble metal-free catalysts, namely manganese dioxide, manganese-polypyrrole-carbon nanotube composite and polyelectrolyte-carbon nanotube composite, have been investigated. These catalysts are sucessfully synthesized and comprehensively characterized. They have been investigated by electrochemical methods and finally applied in MFCs, demonstrated satisfactory performance. In addition, the three catalysts developed represent three promising research directions for noble metal-free oxygen reduction catalysts, and more effort could be made for further improvement by applying different components.

In the future, novel application of MFCs such as bioremediation reactor or on-line sensors could be explored, and our cost-effective membranes and catalysts will facilitate this progress.