Fig. 4. PEC responses of the Ru–ZnP/TiO2/FTO (black), Ru-ref + ZnP-ref/TiO2/FTO (blue), ZnP-ref/TiO2/FTO (red) and Ru-ref/TiO2/FTO (green) electrodes under white light illumination (Win = 35 mW cm–2, λ > 380 nm). The freshly prepared photoanodes with a TiO2 thickness of 12 μm were employed for the measurements. Conditions: external bias: –0.2 V vs. NHE, electrolyte: PB (0.1 M, initial pH 7.3).
