Study on mechanism of enhanced photocatalytic performance of N-doped TiO2/Ti photoelectrodes by theoretical and experimental methods
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Several kinds of N-doped/undoped TiO2 photoelectrodes with different nanostructures have been successfully prepared by anodization method and plasma-based ion implantation (PBII) technique. The morphology and structure of as-prepared photoelectrodes were studied by scanning electron microscopy, X-ray diffraction, and ultra violet/visible light diffuse reflectance spectra. Electronic structure and optical properties were calculated by means of first-principle. Photocatalytic (PC) and photoelectrocatalytic (PEC) performance were measured by the decomposition of terephthalic acid (TA) and Rhodamine B under xenon light illumination. Theoretical calculation results demonstrated that crystal phases have great influence on the electric and optical properties, and N-doped TiO2 photoelectrodes have isolated N2P impurity states nearby the top of the valence band. The optical properties and UV/Vis analysis confirmed that the absorption edge of N–TiO2 emerged red-shift and high photosensitivity. The discrepancy of PC and PEC performance of as-prepared TiO2 photoelectrodes were ascribed to band gap narrowing, N2p impurity states, self-semiconductor coupling effect, and long-range ordered orientation of photogenerated carries originated from applied electric field.
KeywordsTiO2 Rutile Photogenerated Electron Terephthalic Acid Nitrogen Doping
This study was supported by National Natural Science Foundation of China (No. 50978066), National Creative Research Groups of National Natural Science Foundation of China (No. 50821002) and State Key Laboratory of Urban Water Resources and Environment (No. 2010DX03).