采用第一性原理平面波超软赝势方法研究了N,Co共掺杂锐钛矿相TiO2的微观结构和光学性质.结果表明:N,Co共掺杂后TiO2晶格中产生的偶极矩使光生电子-空穴对更有效地分离；在TiO2导带和价带之间形成了新的杂质能级,一方面使吸收带边红移到可见光区,光吸收性能明显增强,另一方面有利于光生电子-空穴对的分离,提高TiO2的光量子效率；与纯TiO2相比,N,Co共掺杂锐钛矿相TiO2带边的氧化还原势只有微小的变化,共掺杂后TiO2的强氧化还原能力得以保持.%The microstructures and optical properties of N and Co-codoped anatase TiO2 are investigated by using the plane-wave ultrasoft pesudopotential method of first-principles. The calculated results show that the octahedral dipole moment of anatase TiO2 increases after N and Co codoping, which is favorable for effective separation of photogenerated electron-hole pairs. Some new impurity energy levels of codoped TiO2 appear between the conduction band and the valence band, which results in the red shift of the absorption wavelength toward visible-light region and an apparent increase in performance of light absorption. These impurity energy levels can promote the effective separation of photogenerated electron-hole pairs, which facilitates the improvement of the photocatalytic efficiency of codoped TiO2. The band edge redox potential of codoped TiO2 is only slightly changed compared with that of pure TiO2, which means that the strong redox capacity of codoping photocatalyst is still excellent.
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