Kinetics of Heterogeneous Electron Transfer at Liquid/Liquid Interfaces As Studied by SECM

Abstract

Scanning electrochemical microscopy (SECM) was used to investigate the kinetics of heterogeneous electron transfer (ET) as a function of driving force at the interface between two immiscible electrolyte solutions. At high driving force, experimental rate constants decreased with increasing overpotential, deviating from predictions based on Butler-Volmer kinetics. This decrease in ET rate with increasing driving force is consistent with Marcus theory inverted region behavior. At low driving force, the potential dependence of the forward and reverse ET rate constants followed Butler-Volmer theory. SECM is also demonstrated to be a useful means of studying the effect of high ionic strength on the kinetics of heterogeneous ET.

Photoinduced Excited State Electron Transfer at Liquid/Liquid Interfaces

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“…Because of that it has enabled the observation of the Marcus-inverted region (see below) and provided a reliable determination of the reorganization free energy. 560,[579][580][581] Spectroelectrochemical methods have been used in recent years to study fastphotoinduced electron transfer at the liquid/liquid interface. [566][567][568][569][570]582 Of particular importance is extending the idea of employing solvent (typically N,N-dimethylaniline or DMA) as an electron donor to the liquid/liquid interface.…”

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