A durable, low-cost bioelectrode material for microbial fuel cells was demonstrated by University of Rochester, NY, researchers.

Metal electrodes corrode when subjected to a wastewater environment, where bacteria donate electrons to drive the electricity generation process. A less expensive option is carbon felt, which is prone to clogging.

The researchers replaced carbon felt with carbon paste paper electrodes fabricated by coating a regular paper strip with carbon paste made from graphite powder and mineral oil, followed by coating with polyaniline. The electrode was constructed as a layered sandwich of paper, carbon paste, a conducting polymer, and a film of Shewanella oneidensis bacteria which extract toxic heavy metal ions from wastewater.

The paper electrode generated a current density of 2.24 A m^-2, compared to 0.94 A m^-2 with the felt anode.