Photocatalytic degradation of methylene blue by TiO₂/Nd₂O₃ composite thin films

To improve the photocatalytic property of TiO₂ thin films, the composite thin films of TiO₂/Nd₂O₃ structure were fabricated by electron-beam physical vapor deposition method, and the photocatalytic property of the fabricated films was experimentally studied in the present work. The XRD and Raman analyses show that the TiO₂/Nd₂O₃ films are mainly hexagonal crystalline phase of Nd₂O₃. The XPS analysis for the chemical state changes of Ti, O and Nd of the basic elements in the films is confirming the electron flow in the internal electric field which generated in the TiO₂/Nd₂O₃ films. The surface morphology shows the lattice distortion which affects the changes in the energy band structure. Moreover, the formation of n-n homojunctions improved the separation efficiency of electrons and holes, and enhanced the catalytic activity. The photocatalytic performance for the methylene blue target dye shows that the sample with TiO₂ thickness of 20-25 nm has better performance, high degradation efficiency and high reaction rate.