Ti/TiO2/Cu2O based electrodes as photocatalysts in PEC cells

Composite Ti/TiO2/Cu2O electrodes were produced by electrodeposition of p-Cu2O nanoparticles over the surface of TiO2 nanotubes generated by one-step electrochemical anodization of titanium. The effect of electrodeposition potential and duration of the electrodeposition experiments on size and morphology of the Cu2O nanoparticles was evaluated by FE-SEM analysis. In order to evaluate the photo-catalytic activity of the composite electrodes, photo-degradation experiments with methylene blue and photo-electrochemical tests were performed. An anodic current was generated by photo-electrochemical tests under visible light and zero bias, confirming the transfer of photo-generated electrons from Cu2O to TiO2. However, in both the photo-degradation and the photo-electrochemical experiments, the photo-catalytic activity of the composite electrodes under simulated solar irradiation (UV + visible) was lower as compared to the application of the bare TiO2 nanotubes electrodes. The mechanisms that could justify such results are thoroughly discussed.