The need for stable oxide-based semiconductors with narrow band gap, able to maximize the exploitation of the visible light portion of the solar spectrum, is a challenging issue for photoelectrocatalytic (PEC) applications. In the present work CuW1−xMoxO4 (Eg = 2.0 eV for x = 0.5), exhibiting a significantly reduced optical band gap Eg compared to isostructural CuWO4 (Eg = 2.3 eV), was investigated as photoactive material for the preparation of photoanodes. CuW0.5Mo0.5O4 electrodes with different thickness (80-530 nm), prepared by a simple solution-based process in the form of multilayer films,