title: Bifunctional silver nanoparticle cathode in microbial fuel cells for microbial growth inhibition with comparable oxygen reduction reaction activity.
abstract: Organic contamination of water bodies in which benthic microbial fuel cells (benthic MFCs) are installed, and organic crossover from the anode to the cathode of membraneless MFCs, is a factor causing oxygen depletion and substrate loss in the cathode due to the growth of heterotrophic aerobic bacteria. This study examines the possible use of silver nanoparticles (AgNPs) as a cathodic catalyst for MFCs suffering from organic contamination and oxygen depletion. Four treated cathodes (AgNPs-coated, Pt/C-coated, Pt/C+AgNPs-coated, and plain graphite cathodes) were prepared and tested under high levels of organics loading. During operation (fed with 50 mM acetate), the AgNPs-coated system showed the highest DO concentration (0.8 mg/L) in the cathode area as well as the highest current (ranging from 0.04 to 0.12 mA). Based on these results, we concluded that (1) the growth of oxygen-consuming heterotrophic microbes could be inhibited by AgNPs, (2) the function of AgNPs as a bacterial growth inhibitor resulted in a greater increase of DO concentration in the cathode than the other tested cathode systems, (3) AgNPs could be applied as a cathode catalyst for oxygen reduction, and as a result (4) the MFC with the AgNPs-coated cathode led to the highest current generation among the tested MFCs.
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 500-712, Korea.
authors.forename: Junyeong
authors.initials: J
authors.lastname: An
authors.forename: Hongrae
authors.initials: H
authors.lastname: Jeon
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Lee
authors.forename: In Seop
authors.initials: IS
authors.lastname: Chang
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development*; D001426:Bacterial Proteins / Q000378:metabolism; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D004566:Electrodes; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010100:Oxygen / Q000378:metabolism*; D012834:Silver / Q000494:pharmacology*; D012995:Solubility / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D012834:Silver; D010100:Oxygen