Hydrodynamics studies of cyclic voltammetry for electrochemical micro biosensors

3rd International Conference on Mathematical Modeling in Physical Sciences

物理学;数学

Adesokan, B.J.^1 ; Quan, X.^2 ; Evgrafov, A.^1 ; Sørensen, M.P.^1 ; Heiskanen, A.^2 ; Boisen, A.^2

Department of Applied Mathematics and Computer Science, Technical University of Denmark, Building 324, Richard Petersens Plads, Kgs. Lyngby

2800, Denmark^1

Department of Micro and Nanotechnology, Technical University of Denmark, Building 345E, 0rsteds Plads, Kgs. Lyngby

2800, Denmark^2

关键词: Applied voltages;    Electrical current;    Electrochemical systems;    Electrode surfaces;    Electrode-electrolyte interfaces;    Electrolyte concentration;    Nernst-Planck equations;    Surface kinetics;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/574/1/012008/pdf
DOI  :  10.1088/1742-6596/574/1/012008

来源: IOP

【 摘 要 】

We investigate the effect of flow rate on the electrical current response to the applied voltage in a micro electrochemical system. To accomplish this, we considered an ion-transport model that is governed by the Nernst-Planck equation coupled to the Navier-Stokes equations for hydrodynamics. The Butler-Volmer relation provides the boundary conditions, which represent reaction kinetics at the electrode-electrolyte interface. The result shows that convection drastically affects the rate of surface kinetics. At a physically sufficient high flow rates and lower scan rates, the current response is limited by the convection due to fresh ions being brought to the electrode surface and immediately taken away before any surface reaction. However, at high flow and scan rates, the Faradaic current overrides current due to convection. The model also allows predicting the effect of varying electrolyte concentration and scan rates respectively.