High Photocatalytic Activity of Rutile TiO2 Induced by Iodine Doping
High Photocatalytic Activity of Rutile TiO2 Induced by Iodine Doping
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DOI：
10.1021/jp911267m
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发表时间：
2010-03
影响因子：
3.7
通讯作者：
Jingfu He;Qinghua Liu;Zhihu Sun;Wensheng Yan;Guobin Zhang;Z. Qi;P. Xu;Ziyu Wu;Shiqiang Wei
中科院分区：
文献类型：
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作者：
Jingfu He;Qinghua Liu;Zhihu Sun;Wensheng Yan;Guobin Zhang;Z. Qi;P. Xu;Ziyu Wu;Shiqiang Wei
为了提高太阳辐射的能量转换，需要在可见光下具有高反应性的光催化剂。利用密度泛函理论研究了碘离子掺杂金红石型TiO2的结构和电子性能。总能量计算表明，碘取代TiO2基体中的钛位在能量上是有利的。电子结构计算表明，碘掺杂在TiO2的价带顶端形成了由i5s态和o2p态组成的离域带。由于这种离域状态，带隙明显缩小了约0.4 eV，光学吸收扩展到可见光区，并且激发的电子-空穴对有望具有更好的迁移率。此外，i掺杂将导带边缘提高到H2/H2O还原水平以上，从而实现了i掺杂金红石型TiO2的高光催化效率。
To improve the energy conversion of solar irradiation, a photocatalyst with high reactivity under visible light is required. Using density functional theory, the structural and electronic properties of iodine cation-doped rutile TiO2 are studied. The total energy calculations show that iodine substituting for titanium sites in TiO2 matrix is energetically favorable. The electronic structure calculations reveal that iodine doping induces a delocalized band consisting of I 5s states and O 2p states at the top of the valence band of TiO2. Due to this delocalized state, the band gap is markedly narrowed by about 0.4 eV, the optical absorption is extended to the visible light region, and the excited electron−hole pairs are expected to have better mobility. Moreover, the conduction band edge is raised above the reduction level of H2/H2O by I-doping, which enables the achievement of high photocatalytic efficiency of I-doped rutile TiO2.