Simulation of edge effects in electroanalytical experiments by orthogonal collocation. Part V. Chronoamperometry at ultramicroelectrode ensembles

Abstract

The use of orthogonal collocation in the treatment of the problem of an array of ultramicroelectrodes is presented and compared to existing digital simulation techniques.

Elucidating Zn and Mg Electrodeposition Mechanisms in Nonaqueous Electrolytes for Next-Generation Metal Batteries

“…Second, resistance to charge transfer at the UME causes a reduction in potential at the center of the electrode surface, while the edge of the UME is largely unaffected. This resistance leads to greater flux and an increase in the magnitude of the potential experienced by the edge of the electrode relative to that at the center of the electrode. , This behavior is colloquially referred to as the “edge effect”. We associate the <100% CE seen in Figure a with an edge effect on the Pt UME.…”

“…This resistance leads to greater flux and an increase in the magnitude of the potential experienced by the edge of the electrode relative to that at the center of the electrode. 34,35 This behavior is colloquially referred to as the "edge effect". We associate the <100% CE seen in Figure 1a with an edge effect on the Pt UME.…”

Numerical simulations of linear scan anodic stripping voltammetry at a modified square array of hemispherical microelectrodes located in a thin-layer cell

“…For each mesh, it has been checked that lowering s e at the mercuryjgel interface has no influence on the results. For the hemisphere, 76 nodes are present inside the mercury drop with 12 nodes at the interface giving s e close to 1 lm (less than 0.1% difference in the overall computed flux with s e $ 0:5 lm) while for the disc, 35 nodes are necessary at the interface due to the edge effects occurring to such a geometry [24,28]. In that case, s e is close to 0.2 lm (less than 0.1% difference with s e $ 0:025 lm).…”

“…Many chronoamperometric studies at microelectrode arrays have been done so far: approximate analytical expressions have been derived for hexagonal, square or random array of inlaid microdisc [14][15][16] and for hemispherical and spherical microelectrodes [17,18] but due to the complexity of the task, numerical simulation has often been used [19][20][21][22][23][24][25][26]. However, the same general behaviour is reported in each case: at short times, the current response of the array can be simply predicted by the sum of the currents occurring at each microelectrode.…”

Minimum grid digital simulation of chronoamperometry at a disk electrode

“…It was noticed early that the ultramicrodisk and -band have an edge problem of a current density singularity, both experimentally [7] and theoretically or by simulation [1,3,[8][9][10][11][12][13][14][15][16][17][18][19][20][21], and the singularity is implicit in Saito's 1968 work [22], which is the source for the steady state value of the current at a disk (although Saito did not remark on the edge effect). The edge effect led Gavaghan [23] to design a mesh for the simulation of the disk that used very unequal intervals, concentrated not only near the disk surface but also at its edge.…”