Pulse-opencircuit voltammetry: A novel method characterizes bioanode performance from microbe-electrode interfacial processes

Bioanode is a key component of bioelectrochemical systems, but the methods characterizing its resistance distribution are lacked. We propose a novel pulse-opencircuit voltammetry (POV) based on the analytical principle clarified from the electron flow pathways of microbe-electrode interfacial processes (MEIPs). A dual-cathode cell is designed to provide an experimental platform for ensuring precise data acquisition of bioanodes. This POV method enables to measure steady state polarization curves and ohmic potential loss curves by integrating potentiostatic discharge and current interruption techniques. They determines reaction resistance (R-B,R-act) and ohmic resistance (R-B,R-ohm) of biofilm with the assistance of impedance spectroscopy measuring material resistance. The results of various bioanodes demonstrate that R-B,R- act is the principal limiting factor and its value relies on catabolism state. Whilst R-B,R- ohm is relevant to extracellular electron transfer behaviors. They are two useful indicators of the dynamic evaluation of biofilm. We anticipate that this method together with the cell platform is accessible to users and has wide applications in bioanode construction and electroactive bacteria investigation.

Automated summary

This article introduces a novel pulse-open circuit voltammetry (POV) method for characterizing the resistance distribution of bioanodes. The method allows for the measurement of reaction resistance and ohmic resistance of biofilms by integrating potentiostatic discharge and current interruption techniques. The results show that the reaction resistance is the main limiting factor, while the ohmic resistance is related to extracellular electron transfer behaviors. The method and cell platform have wide applications in bioanode construction and electroactive bacteria investigation.