Nano-scale polar-nonpolar oxide heterostructures for photocatalysis
Nano-scale polar-nonpolar oxide heterostructures for photocatalysis
复制标题
用于光催化的纳米级极性-非极性氧化物异质结构
DOI：
10.1039/c5nr08689b
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发表时间：
2016-01-01
期刊：
影响因子：
6.7
通讯作者：
Zhao, Jin
中科院分区：
文献类型：
--
作者：
Guo, Hongli;Saidi, Wissam A.;Zhao, Jin
We proposed based on first principles density functional theory calculations that a nano-scale thin film based on a polar-nonpolar transition-metal oxide heterostructure can be used as a highly-efficient photocatalyst. This is demonstrated using a SrTiO3/LaAlO3/SrTiO3 sandwich-like heterostructure with photocatalytic activity in the near-infrared region. The effect of the polar nature of LaAlO3 is two-fold. First, the induced electrostatic field accelerates the photo-generated electrons and holes into opposite directions and minimizes their recombination rates. Hence, the reduction and oxidation reactions can be instigated at the SrTiO3 surfaces located on the opposite sides of the heterostructure. Second, the electric field reduces the band gap of the system making it photoactive in the infrared region. We also show that charge separation can be enhanced by using compressive strain engineering that creates ferroelectric instability in STO. The proposed setup is ideal for tandem oxide photocatalysts especially when combined with photoactive polar materials.
