Nyquist and Mott-Schottky plots are common analytical tools generally used in electrochemistry to model the equivalent circuit that better describes the interface in such systems. Using the Mott-Schottky analysis we can determine 𝑁 𝑑 and 𝑉 𝑓𝑏 values by a simple linear fit to the experimental data expressed as 1 𝐶 ⁄ as a function of the applied potential. This analysis works well for model systems: homogeneous and continuous photoanodes, sufficiently thick. In our case, the photoanodes consist of nanorods, with sizes of few hundreds of nanometers, perpendicular to the FTO substrate. The linear fit from the Mott Schottky analysis does not give accurate absolute values for 𝑁 𝑑 and 𝑉 𝑓𝑏 and therefore they should not be simply compared to the literature, especially when applied on photoanodes presenting different morphology. We use these values here only to compare the electric properties between the S1 and S2 samples.