Hierarchical micro/nano structures of carbon composites as anodes for microbial fuel cells

We demonstrate the utility of hierarchical micro/nano structures of electrically conductive carbon composites as anodes for microbial fuel cells (MFCs). To construct the hierarchical structures, carbon nanotubes (CNTs) were directly grown on micro-porous graphite felts at high densities. Using the CNT-modified felts as anodes, power outputs from MFCs were increased ∼7 fold compared to those with bare graphite-felt anodes. We also show that this power improvement is sustainable even in MFCs operated with naturally occurring microbial communities. These results suggest the wide utility of the hierarchical micro/nano structures of conductive carbon composites for bio-electrochemical processes.