Comparative study of a transient redox reaction on a single electrode microdisk using finite element analysis.

This paper presented a finite element method (FEM) analysis for a transient redox reaction on a single electrode microdisk via commercial software COMSOL Multiphysics®. The software capabilities in modelling have been well documented, however, a direct comparison of the 1-dimension (1D), 2-dimension (2D) axisymmetric, and 3-dimension (3D) models for electrode microdisk is scarcely available. The developed model is for cyclic voltammetry under semi-infinite spherical diffusion. Mesh refinement with its consequent number of elements (noe), computation time (t_com), and current, I_(t) was compared on the 1D, 2D axisymmetric, and 3D model. This paper proved the software's consistency to produce less than 3% error between simulation and analytical results across all dimensions. 1D simulation took around 3 minutes to complete, giving less than 0.1% error. While the 2D axisymmetric simulation completed around 10 minutes with 0.5% error. On very fine mesh using a 3D model can yield a simulation with an error of 2.5%. It has the drawback of taking significantly longer t_com to complete. A slight discrepancy between 2D axisymmetric and 3D simulation results on finest meshing recorded to have less than 3% difference and that is due to CPU memory limit. Further investigations on complex electrochemistry using this platform are justified and highly recommended. [ABSTRACT FROM AUTHOR]