title: Analysis of bio-anode performance through electrochemical impedance spectroscopy.
abstract: In this paper we studied the performance of bioanodes under different experimental conditions using polarization curves and impedance spectroscopy. We have identified that the large capacitances of up to 1 mF·cm(-2) for graphite anodes have their origin in the nature of the carbonaceous electrode, rather than the microbial culture. In some cases, the separate contributions of charge transfer and diffusion resistance were clearly visible, while in other cases their contribution was masked by the high capacitance of 1 mF·cm(-2). The impedance data were analyzed using the basic Randles model to analyze ohmic, charge transfer and diffusion resistances. Increasing buffer concentration from 0 to 50mM and increasing pH from 6 to 8 resulted in decreased charge transfer and diffusion resistances; lowest values being 144 Ω·cm(2) and 34 Ω·cm(2), respectively. At acetate concentrations below 1 mM, current generation was limited by acetate. We show a linear relationship between inverse charge transfer resistance at potentials close to open circuit and saturation (maximum) current, associated to the Butler-Volmer relationship that needs further exploration.
authors: Sub-department of Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors: Annemiek
authors: A
authors: ter Heijne
authors: Wetsus, Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands.
authors: Olivier
authors: O
authors: Schaetzle
authors: Photovoltaic and Optoelectronics Devices Group, Departament de Física, Universitat Jaume, Av. Sos Baynat s/n, 12006 Castelló de la Plana, Spain.
authors: Sixto
authors: S
authors: Gimenez
authors: Photovoltaic and Optoelectronics Devices Group, Departament de Física, Universitat Jaume, Av. Sos Baynat s/n, 12006 Castelló de la Plana, Spain.
authors: Lucia
authors: L
authors: Navarro
authors: Wetsus, Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands.
authors: Bert
authors: B
authors: Hamelers
authors: Photovoltaic and Optoelectronics Devices Group, Departament de Física, Universitat Jaume, Av. Sos Baynat s/n, 12006 Castelló de la Plana, Spain. Electronic address: fabresan@fca.uji.es.
authors: Francisco
authors: F
authors: Fabregat-Santiago
mesh_terms: D000085:Acetates / Q000737:chemistry; D001674:Bioelectric Energy Sources; D002021:Buffers; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006863:Hydrogen-Ion Concentration
chemical_list: D000085:Acetates; D002021:Buffers; D006108:Graphite
keywords: Charge transfer; Diffusion; Electrochemical impedance spectroscopy; Internal resistance; Microbial fuel cell