Cu-Cu2O-TiO2 Nanojunction Systems with an Unusual Electron-Hole Transportation Pathway and Enhanced Photocatalytic Properties

Multicomponent CuCu2OTiO2 nanojunction systems were successfully synthesized by a mild chemical process, and their structure and composition were thoroughly analyzed by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The as-prepared CuCu2OTiO2 (3 and 9h) nanojunctions demonstrated higher photocatalytic activities under UV/Vis light irradiation in the process of the degradation of organic compounds than those of the CuCu2O, CuTiO2, and Cu2OTiO2 starting materials. Moreover, time-resolved photoluminescence spectra demonstrated that the quenching times of electrons and holes in CuCu2OTiO2 (3h) is higher than that of CuCu2OTiO2 (9h); this leads to a better photocatalytic performance of CuCu2OTiO2 (3h). The improvement in photodegradation activity and electronhole separation of CuCu2OTiO2 (3h) can be ascribed to the rational coupling of components and dimensional control. Meanwhile, an unusual electronhole transmission pathway for photocatalytic reactions over CuCu2OTiO2 nanojunctions was also identified.