title: Open circuit (mixed) potential changes upon contact between different inert electrodes-size and kinetic effects.
abstract: We investigate the principle of the open circuit potential (OCP) change upon a particle collision event based on mixed potential theory and confirmed by a mimic experiment in which we studied the changes in the OCP when two different electrodes (Pt and Au) are brought into contact in a solution that contains some irreversible redox couples. A micrometer-sized Au ultramicroelectrode, when connected in parallel to a Pt micro- or nanoelectrode, showed clearly measurable OCP changes whose magnitude matches well with that predicted by a simplified mixed potential theory for a pair of different electrode materials. On the basis of the study, each electrode establishes a different mixed potential involving two or more half reactions that have different heterogeneous electron transfer kinetics at different electrodes and the OCP changes are very sensitive to the relative ratio of the rate constant of the individual half reaction at different materials.
authors.affiliation: Center for Electrochemistry, Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Jun Hui
authors.initials: JH
authors.lastname: Park
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhou
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Percival
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Fu-Ren F
authors.initials: FR
authors.lastname: Fan
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Bard
mesh_terms: D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010984:Platinum; D006046:Gold