Bonding and Electron Energy-Level Alignment at Metal/TiO2 Interfaces: A Density Functional Theory Study

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• 作者：Hungru Chen ; Peng Li ; Naoto Umezawa ; Hideki Abe ; Jinhua Ye ; Kenji Shiraishi ; Akio Ohta ; Seiichi Miyazaki
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：March 17, 2016
• 年：2016
• 卷：120
• 期：10
• 页码：5549-5556
• 全文大小：646K
• ISSN：1932-7455

文摘

Metal/TiO₂ interfaces have been extensively studied because of their importance in electronic devices, electrochemical cells, and photocatalysis. In this article, we present our studies on electronic structures for anatase TiO₂(001)/fcc-metal(001) (metal = Pt, Pd, or Au) interfaces using first-principles calculations. It is demonstrated that the Schottky barrier height depends on the metal work function and significantly decreases at an interface with strong adhesion between the metal and TiO₂. The sizable reduction of the barrier height is a consequence of dipole formation at the interface due to electron transfer from TiO₂ to the metal. The formation of dipoles at the Pt/TiO₂ interface is supported by our experimental results for a core-level binding-energy shift in Pt clusters loaded on the surface of TiO₂. Differences in the bonding and antibonding characters of metal–O bonds for the three metals are discussed based on the projected densities of states given by our density-functional theory calculations.