What Role Does the Electric Double Layer Play in Redox Reactions at Planar Electrostatically Charged Insulating Surfaces?

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Redox reactions have been observed when an electrostatically charged insulator is placed in contact with a solution, and this phenomenon is referred to as single-electrode electrochemistry. In this study we explore how important is the chemical reactivity of the charge carriers on the surface compared to the voltage caused by the density of charges on the surface which set up an electric double layer. We address complications arising from the surface potential’s dependence upon the electrolyte concentration caused by the fixed surface charge density of the electrode. We present an analytical solution for the effective potential in single-electrode electrochemistry at a planar surface and show that it is not the same as the potential at the insulating surface. We reach two major conclusions: (1) the voltage applied to the reaction from discharging the electrode approaches a limiting value, and (2) the majority of single-electrode reactions are caused primarily by the chemical reactivity of the charge carrier on the electrode surface and not from discharging the static charge on the electrode.