Numerical simulations of phenomena observed at hot microelectrodes: Inlaid microdisk

In this paper we describe numerical simulations of a number of physico-chemical phenomena observed at disk microelectrodes polarized with a high frequency ac waveform. These phenomena include resistive heating of an electrolyte solution surrounding a microelectrode, electrothermal flow of the solution and electrochemical mass transport of dissolved redox species. The main purpose of doing these simulations was to provide the required theoretical background to the previously obtained experimental data. It is shown that the simulated linear flow rate of the solution is proportional to the voltage across the solution resistance in the power four and inversely proportional to the radius of the microelectrode. Thus this supports the idea that the convection at hot microelectrodes is driven primarily by the electrothermal flow. Simulations of the Faradaic current agree semi-quantitatively with the experimental observations. We have identified possible reasons for the observed discrepancy between the two sets of data.

• We described numerical simulations of temperature distribution around ac heated disk microelectroelectrodes.
• Simulations of electrothermal force around ac heated microelectrodes.
• Simulations of electrothermal convection.
• Simulations of steady-state voltamograms at ac heated disk microelectroelectrodes.
• Simulations agree semi-quantitatively with the experimental observations.