A facile hydrothermal deposition of ZnFe2O4 nanoparticles on TiO2 nanotube arrays for enhanced visible light photocatalytic activity

ZnFe2O4 coupled TiO2 nanotube arrays (ZnFe2O4-TiO2 NTAs) were synthesized by modifying TiO2 nanotube arrays with ZnFe2O4 nanoparticles. Self-organized TiO2 NTAs with a tube diameter of 100 nm and length of 400 nm were prepared by an electrochemical anodization method. ZnFe2O4 nanoparticles were deposited on the surface of TiO2 nanotubes through a facile hydrothermal route. The modification of ZnFe2O4 nanoparticles extended the photoresponse of TiO2 nanotube arrays into the visible light region. Under visible light irradiation, a 12-fold enhancement in photocatalytic activity was achieved using ZnFe2O4-TiO2 NTAs compared with TiO2 NTAs. The enhanced photogenerated electron-hole separation and improved transfer of photogenerated charge carriers were responsible for the increased photocatalytic activity of ZnFe2O4-TiO2 NTAs. This approach provides a simple method for synthesizing a variety of nanoparticle-modified one-dimensional nanomaterials.