学术报告 The Nature of Excess Electrons and their Roles in the Photocatalytic Activity of Reduced TiO2
【报告题目】 The Nature of Excess Electrons and their Roles in the Photocatalytic Activity of Reduced TiO2
【报 告 人】 Prof. Li-Min Liu
Beijing Computational Science Research Center
【时 间】 2017-06-07 星期三 16:00
【地 点】 北园物理楼106
Titanium dioxide (TiO2), as a typical visible-light photocatalyst, attracts great attentions from both the theory and experiment. The defect TiO2 is the vital topic of the semiconducting materials both because of the fundamental important of excess electrons and the widely applications. Transitions from the defect states are important for both the photoadsorption and photoactivity, however, the character of the electronic excited states is still unclear due to the great difficulty to experimentally characterize the unoccupied states. Computer simulations are one of the effective way to explore the related processes. In this talk, the detailed resonance states and its effects on the photoabsorption of defective TiO2 are carefully explored with the first-principles calculations. The results show that the n-type defect TiO2 exhibits two typical states, one is the gap state at ~1 eV below Fermi level EF and the other at ~2.5 eV above EF in the because of the Jahn-Teller effect, respectively. The calculated oscillation strength of the transition from the gap state to the corresponding resonance state at 2.5 eV further indicates the defect can enhance the photoabsorption.
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Dr. Li-Min Liu received his PhD degree in Materials Science from the Institute of Metal Research, Chinese Academy of Sciences, in 2006. During his PhD study, he visited Queen’ University of Belfast, U.K., for a year. He has worked in Fritz-Haber-Institut (Germany), University College London (U.K.) and Princeton University. Since 2011, he joined CSRC as a tenure-tracked associated professor. In 2012, he was awarded National Support Program for Top-notch Young Talents and the excellent young scientist fund of NSFC. His research interests focus on the nanocatalysts, TiO2-based photocatalysis, and aqueous water solid interfaces for the electrocatalysis and fuel cell. He has published about 100 papers on the high-impact journals, such as Chem. Rev., Nat. Com., EES, JACS.
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