Ultimately, this clear difference was not observed as the Nyquist plots for devices operating in aprotic solvents continued to show two simultaneous processes during the photoelectrochemical reduction. This is shown in Figure , where again the resistances of two processes are observed to increase at voltages negative of the onset voltage. The magnitudes of these two resistances are approximately in agreement with those of a device operating in a protic electrolyte at the same current density.