Screen-printing is a commonly used method for the preparation of photoelectrodes. Although previous studies have explored the effect of the number of printed layers on the efficiency of dye-sensitized solar cells, its interplay with the photoelectrocatalytic properties of the electrodes has rarely been examined. This study focuses on this issue by studying the photoelectrocatalytic oxidation of methanol over TiO2 electrodes. The number of layers was varied between one and four and the activity was determined at four different wavelengths (327, 338, 370, and 385 nm) at an applied potential of 0.5 V vs. NHE. A strong dependency on the illumination wavelength was observed. While the one-layer electrode is the most efficient one during the illumination with 327 and 338 nm, it shows the lowest activity under illumination with 385 nm. Modelling and quantification of the electron diffusion length helped explain why the two-layer electrode showed the most consistent efficiencies across all conditions. Our work shows that the optimization of photoelectrocatalytic processes should include the number of layers as a key variable.