We found that the potential-modulated UV-vis reflectance (electroreflectance, ER) spectrum measured with linearly polarized incident light at an edge-plane graphite (EPG) electrode with adsorbed redox species shows surface anisotropy. At a hemin or methylene blue-adsorbed EPG electrode, s-polarized incident light gave rise to greater ER response than p-polarized when the c axis of the graphite electrode is parallel to the plane of incidence, while when the c axis is perpendicular to the plane of incidence p-polarized light gave rise to greater response. The anisotropy was also observed for an EPG electrode coated with a Nafion film in which adsorptive species was incorporated. In contrast, methylviologen-incorporated Nafion films did not produce the anisotropy. The possible origin of the anisotropy was discussed in light of the surface morphology of the EPG as observed by the SEM.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry