p-n Heterojunction photoelectrodes composed of Cu2O-loaded TiO2 nanotube arrays with enhanced photoelectrochemical and photoelectrocatalytic activitiesElectronic supplementary information (ESI) available. See DOI: 10.1039/c3ee24162a

Cu 2 O/TiO 2 p-n heterojunction photoelectrodes were prepared by depositing different amounts of p-type Cu 2 O nanoparticles on n-type TiO 2 nanotube arrays ( i.e. , forming Cu 2 O/TiO 2 composite nanotubes) via an ultrasonication-assisted sequential chemical bath deposition. The success of deposition of Cu 2 O nanoparticles was corroborated by structural and composition characterizations. The enhanced absorption in the visible light region was observed in Cu 2 O/TiO 2 composite nanotubes. The largely improved separation of photogenerated electrons and holes was revealed by photocurrent measurements. Consequently, Cu 2 O/TiO 2 heterojunction photoelectrodes exhibited a more effective photoconversion capability than TiO 2 nanotubes alone in photoelectrochemical measurements. Furthermore, Cu 2 O/TiO 2 composite photoelectrodes also possessed superior photoelectrocatalytic activity and stability in the degradation of Rhodamine B. Intriguingly, by selecting an appropriate bias potential, a synergistic effect between electricity and visible light irradiation can be achieved. Cu 2 O/TiO 2 p-n heterojunction photoelectrodes for the degradation of Rhodamine B via a synergistic effect between electricity and visible light irradiation.