This presentation will describe a detailed framework for modeling and interpreting the data from a cyclic voltammetric measurement of adsorbed redox monolayers on semiconductor electrodes. A three layer model consisting of the semiconductor space charge layer, a surface layer, and a diffuse electrolyte layer is presented that articulates the interplay between electrostatic, thermodynamic, and kinetic factors in the electrochemistry of a redox adsorbate on a semiconductor. New expressions are derived that describe the charging and faradaic current densities individually and an algorithm is demonstrated that allows for the calculation of the total current density in a cyclic voltammetry measurement as a function of changes in the physical properties of the system (e.g. surface recombination, dielectric property of the surface layer, and electrolyte concentration). The most profound point from this analysis is that the faradaic and charging current densities are coupled. That is, the common assumption that these contributions to the total current are independent is false. Their inter-relation can influence the interpretation of the charge-transfer kinetics under certain experimental conditions. Experimental measurements for redox molecules adsorbed on Si will be presented and understood within the described framework.

A quantitative model for the heterogeneous charge transfer between semiconductor (Photo)electrodes and redox adsorbates - The charging and faradaic currents are coupled

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.