Impedance and Thermodynamic Analysis of Bioanode, Abiotic Anode, and Riboflavin-Amended Anode in Microbial Fuel Cells

Abstract

Understanding exoelectrogenic reactions of the bioanode is limited due to its complexity and the absence of analytics. Impedance and thermodynamics of bioanode, abiotic anode, and riboflavin-amended anode were evaluated. Activation overpotential of the bioanode was negligible compared with that of the abiotic anode. Impedance spectroscopy shows that the bioanode had much lower charge transfer resistance and higher capacitance than the abiotic anode in low frequency reaction. In high frequency reaction, the impedance parameters, however, were relatively similar between the bioanode and the abiotic anode. At open-circuit impedance spectroscopy, a high frequency arc was not detected in the abiotic anode in Nyquist plot. Addition of riboflavin induced a phase angle shift and created curvature in high-frequency arc of the abiotic anode, and it also drastically changed impedance spectra of the bioanode.

Improved structures of stainless steel current collector increase power generation of microbial fuel cells by decreasing cathodic charge transfer impedance

“…2), showing that abiotic catalyst in cathode is the main source of activation loss rather than the anodic microbial catalyst. This result is coincident with the previous observation of negligible activation loss in the bioanode [36].…”

“…Their charge transfer resistance difference might be due to their different applied currents. According to a previous study, anodic charge transfer impedance decreased as current density increased, but cathodic charge transfer impedance was almost unaffected by applied potential or current for EIS [36]. Therefore, the change in charge transfer resistance among the MFCs might be attributed to the different cathode structures rather than the applied currents for EIS.…”

Electricity Generation by Shewanella decolorationis S12 without Cytochrome c

“…Electrochemical impedance spectroscopy (EIS) of the MFC anodes was analyzed using an electrochemical workstation (Corrtest, China). Before analysis, the cell voltage of each MFC was controlled at their open-circuit voltages for 30 min as suggested by previous reports ( Jung et al, 2012 ). A frequency range from 10 mHz to 100 kHz with an AC signal of ±10 mV amplitude was used.…”

A comprehensive impedance journey to continuous microbial fuel cells

“…Ag/AgCl, 3 M KCl (+199 mV vs. SHE) was the reference electrode and coiled Pt wire functioned as a counter electrode (CE). Carbon felt (100 cm 2 ) was used as anode, while a cold-rolled activated carbon gas diffusion electrode (100 cm 2 ), namely VITO CORE™, was used as cathode [23]. To prevent interference of gases (O 2 or H 2 ) which can be produced at the CE during the polarization measurements, Zirfon® ion permeable separator was placed between the working electrode and the CE.…”

“…Prior to its use, the Zirfon® membrane was pre-treated to improve its wettability, by placing it in 70°C phosphate buffer (PBS) for 2 h. Sodium acetate (10 mM) was used as a substrate. The composition of the PBS has been detailed elsewhere [21][22][23]. The electrolyte was fed from an external reservoir bottle which was constantly stirred by magnetic means at 120 rpm.…”