Comparison of different chemical treatments of brush and flat carbon electrodes to improve performance of microbial fuel cells

Abstract

Anodes in microbial fuel cells (MFCs) can be chemically treated to improve performance but the impact of treatment on power generation has not been examined for different electrode base materials. Brush or flat anodes were chemically treated and then compared in identical two-chambered MFCs using the electrode potential slope (EPS) analysis to quantify the anode resistances. Flat carbon cloth anodes modified with carbon nanotubes (CNTs) produced 1.42 ± 0.06 W m^-2, which was 3.2 times more power than the base material (0.44 ± 0.00 W m^-2), but less than the 2.35 ± 0.1 W m^-2 produced using plain graphite fiber brush anodes. An EPS analysis showed that there was a 90% decrease in the anode resistances of the CNT-treated carbon cloth and a 5% decrease of WO₃ nanoparticle-treated brushes compared to unmodified controls. Certain chemical treatments can therefore improve performance of flat anodes, but plain brush anodes achieved the highest power densities.

Keywords: Brush anode; Carbon nanotubes; Ferricyanide cathode; Ionic liquid polymer; Nanoparticles.