Potential Modulated Attenuated Total Reflectance Spectroscopy of Prussian Blue Films on ITO

Abstract

Potential modulated attenuated total reflectance (PM‐ATR) spectroscopy has been employed to study charge transfer processes in Prussian blue (PB) films deposited on indium tin oxide (ITO) electrodes. PM‐ATR is a planar waveguide‐based spectroelectrochemical technique in which the optical response of an electroactive film is measured as a function of applied potential and modulation frequency. The multiple internal reflection geometry of PM‐ATR provides a significant sensitivity advantage over the single external reflectance geometry that has been employed in most prior electroreflectance studies. The apparent electron transfer rate of PB on ITO obtained using PM‐ATR was compared to that obtained with conventional cyclic voltammetry; the respective rates, 0.33 ± 0.15 s −1 (n = 3) and 0.71 ± 0.37 s −1 (n = 10), are in good agreement.