Khan Matiullah, Lan Zhenghua, Zeng Yi
State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Shanghai Career Metallurgy Furnace Material Co., Ltd., Shanghai 201908, China.
Materials (Basel). 2018 Jun 5;11(6):952. doi: 10.3390/ma11060952.
Due to the high formation energy of Indium interstitial defect in the TiO₂ lattice, the most probable location for Indium dopant is substitutional sites. Replacing Ti by In atom in the anatase TiO₂ shifted the absorption edge of TiO₂ towards visible regime. Indium doping tuned the band structure of TiO₂ via creating In 5p states. The In 5p states are successfully coupled with the O 2p states reducing the band gap. Increasing In doping level in TiO₂ improved the visible light absorption. Compensating the charge imbalance by oxygen vacancy provided compensated Indium doped TiO₂ model. The creation of oxygen vacancy widened the band gap, blue shifted the absorption edge of TiO₂ and declined the UV light absorption. The 2.08% In in TiO₂ is the optimal Indium doping concentration, providing suitable band structure for the photoelectrochemical applications and stable geometrical configuration among the simulated models. Our results provide a reasonable explanation for the improved photoactivity of Indium doped TiO₂.
由于铟在TiO₂晶格中的间隙缺陷形成能较高，铟掺杂剂最可能的位置是替代位点。在锐钛矿TiO₂中用铟原子取代钛原子，使TiO₂的吸收边向可见光区域移动。铟掺杂通过产生In 5p态来调节TiO₂的能带结构。In 5p态成功地与O 2p态耦合，减小了带隙。增加TiO₂中的铟掺杂水平可改善可见光吸收。通过氧空位补偿电荷不平衡，得到了补偿型铟掺杂TiO₂模型。氧空位的产生拓宽了带隙，使TiO₂的吸收边蓝移，并降低了紫外光吸收。TiO₂中2.08%的铟是最佳铟掺杂浓度，为光电化学应用提供了合适的能带结构，并且在模拟模型中具有稳定的几何构型。我们的结果为铟掺杂TiO₂光活性的提高提供了合理的解释。
