title: Nernst-ping-pong model for evaluating the effects of the substrate concentration and anode potential on the kinetic characteristics of bioanode.
abstract: Understanding the electron-transfer mechanism and kinetic characteristics of bioanodes is greatly significant to enhance the electron-generating efficiencies in bioelectrochemical systems (BESs). A Nernst-ping-pong model is proposed here to investigate the kinetics and biochemical processes of bioanodes in a microbial electrolysis cell. This model can accurately describe the effects of the substrate (including substrate inhibition) and the anode potential on the current of bioanodes. Results show that the half-wave potential positively shifts as the substrate concentration increases, indicating that the rate-determining steps of anodic processes change from substrate oxidation to intracellular electron transport reaction. The anode potential has negligible effects on the enzymatic catalysis of anodic microbes in the range of -0.25 V to +0.1 V vs. a saturated calomel electrode. It turns out that to reduce the anodic energy loss caused by overpotential, higher substrate concentrations are preferred, if the substrate do not significantly and adversely affect the output current.
authors.affiliation: Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry & Environment, Beihang University, Beijing 100191, PR China.
authors.forename: Sikan
authors.initials: S
authors.lastname: Peng
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Liang
authors.forename: Peng
authors.initials: P
authors.lastname: Diao
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Lan
authors.forename: Yuhan
authors.initials: Y
authors.lastname: Yang
authors.forename: Shanfu
authors.initials: S
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001674:Bioelectric Energy Sources; D002384:Catalysis; D004560:Electricity; D055664:Electrochemical Techniques; D004566:Electrodes; D007700:Kinetics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D019346:Sodium Acetate / Q000737:chemistry
chemical_list: D019346:Sodium Acetate