Growth of Cu2O/TiO2 heterojunction and its photoelectrochemical properties

In this paper, the Cu2O/TiO2 heterostructure is composed of Cu2O particles and TiO2 nanoring/nanotube (R/T). The high order TiO2(R/T) were prepared by two-step anodization. With small diameter Cu2O particles deposited on the TiO2(R/T) by a simple thermal decomposition process, the photoelectrochemical properties of the TiO2(R/T) has been enhanced. As-prepared samples were characterized by scanning electron microscopy, X-ray diffraction and energy dispersive spectrometer. The photoelectrochemical behavior of the samples was studied through electrochemical impedance spectroscopy and photo-to-current conversion efficiency measurement. It was found that the combination of Cu2O with TiO2(R/T) could not only improve the carrier separation efficiency, but also extend the optical response range of TiO2(R/T) to the visible light region. Finally, the mechanism that Cu2O can enhance the photoelectrochemical properties of TiO2(R/T) is discussed. (C) 2019 Elsevier B.V. All rights reserved.