title: Photocatalytically improved azo dye reduction in a microbial fuel cell with rutile-cathode.
abstract: Reductive decolorization of azo dye in wastewater was investigated in a dual-chamber microbial fuel cell (MFC) equipped with cathodes made of graphite or rutile-coated graphite. Rapid reduction of methyl orange (MO) with concomitant electricity production was achieved when the rutile-coated cathode was irradiated by visible light. The electrochemical impedance spectra (EIS) indicate that the polarization resistance (R(p)) of the rutile-cathode MFC decreased from 1378 Omega in dark to 443.4 Omega in light, demonstrating that photocatalysis of rutile can enhance the cathodic electron transfer process. The combination of the biologically active anode and photocatalysis-supported cathodic reduction of MO obeyed the pseudo-first-order kinetics. The analysis of decolorization products indicates that the azo bond of MO was probably cleaved by photoelectrons at the irradiated rutile-cathode, resulting in the products of colorless hydrazine derivatives. In addition, concurrently enhanced electricity generation in the MFCs involving photocatalyzed cathodic reduction of MO was observed throughout this study.
authors.affiliation: The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, PR China.
authors.forename: Hongrui
authors.initials: H
authors.lastname: Ding
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Anhuai
authors.initials: A
authors.lastname: Lu
authors.forename: Song
authors.initials: S
authors.lastname: Jin
authors.forename: Chao
authors.initials: C
authors.lastname: Quan
authors.forename: Changqiu
authors.initials: C
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zeng
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Yan
mesh_terms: D001391:Azo Compounds / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D002384:Catalysis; D004396:Coloring Agents / Q000378:metabolism*; D004563:Electrochemistry; D004566:Electrodes; D007700:Kinetics; D010084:Oxidation-Reduction; D010777:Photochemistry
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents