Novel electrode materials to enhance the bacterial adhesion and increase the power generation in microbial fuel cells (MFCs)

In this study, two novel electrode materials were tested to enhance bacterial adhesion and increase power production in microbial fuel cells (MFCs). Polypyrrole (PPy), a nontoxic conductive polymer, was coated on the plain carbon cloth electrodes to bridge with the biopolymers on bacterial cell membranes and to improve the power production. The PPy-coated electrodes increased the initial power from 20 mW/m(2) to 160 mW/m(2) in the first 4-day period. But there was no clear difference between two PPy coating thicknesses (5-cycle coating and 50-cycle coating) in terms of the bacterial adhesion and power production. Granular activated carbon (GAC), a commonly used bacterial support material with high surface area, exhibited a good bacterial adhesion and high power output. GAC-SCMFCs (single chamber MFCs) generated 5 W/m(3) and maintained the peak power for 6 days. Compared with plain carbon cloth electrodes, GAC-SCMFCs had lower internal resistances and higher power generations. However, GAC-SCMFCs had lower columbic efficiency and energy conversion efficiency than the conventional two chamber MFCs.