A rapid and energy-efficient method was presented for preparing CuO-TiO_2 nanotube arrays.TiO_2 nanotube arrays were first prepared by anodic oxidation using titanium anode and platinum cathode.Then,the formed TiO_2 nanotube arrays and Pt were used as cathode and anode,respectively,for subsequent formation of CuO-TiO_2 nanotube arrays,through an electrochemical process in a solution of 0.1 mol/L CuSO_4.The morphology and composition of the CuO-TiO_2 nanotube arrays were characterized using field-emission scanning electron microscopy,X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),and UV-Vis diffusion reflection spectroscopy(UV-Vis DRS).XPS and XRD analyses suggested that the Cu element in the nanotubes existed in CuO form,and its content changed along with the voltage during the second electrochemical process.The photocatalytic activities of the CuO-TiO_2 nanotube arrays were evaluated by the degradation of a model dye,rhodamine B.The results showed that Cu incorporation aroused wide visible-light adsorption and improved the photocatalytic efficiency of TiO_2nanotube arrays significantly under visible-light irradiation.The stability of the CuO-TiO_2 nanotube arrays was also detected.
Haijin LiuYingling WangGuoguang LiuYuan RenNan ZhangGang WangTong Li
