Aligning Electronic Energy Levels on the Anatase TiO₂(101) Surface

Jun-jie ZHAO, Department of high pressure oxygen,, The Affiliated First Hospital, Fujian Medical University, Fuzhou 350005 , China;
Jun CHENG, Department of Chemistry,College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China.;Follow

Corresponding Author

Jun CHENG(chengjun@xmu.edu.cn)

Abstract

As one of the most commonly-used materials for photocatalysis and solar energy conversion, titanium dioxide (TiO₂) has been extensively studied for more than 40 years. Its photoelectrochemical activity crucially depends on the band positions at the interface. In this work, the valence band maximum (VBM) and conduction band minimum (CBM) of a model TiO₂ surface are computed using the standard work function method at the level of Perdew-Burke-Ernzerhof (PBE) density functional, which are then converted to the scale of the standard hydrogen electrode (SHE) by subtracting the absolute SHE potential. Comparing with the rutile TiO₂(110) surface, we find a similar upshift in the VBM and CBM upon the adsorption of water molecules on the anatase TiO₂(101) surface, and the band gap error intrinsic to the PBE functional can be mainly attributable to mis-positioning of the VBM. In addition, in contrast to the finding on the rutile TiO₂(110) surface that the adsorption of 1 monolayer water largely recovers the band alignment of the aqueous interface, our preliminary calculations indicate that on the anatase TiO₂(101) surface there is a considerable difference between the simplified model with the adsorption of 1 monolayer water and the fully solvated interface, suggesting the necessity to include the water molecules beyond the first adsorption layer in order to realistically represent the anatase TiO₂water interface.

Graphical Abstract

Keywords

anatase, valence band maximum, conduction band minimum, band alignment, density functional theory

DOI Link

https://doi.org/10.13208/j.electrochem.160418

Publication Date

2017-02-28

Online Available Date

2016-05-16

Revised Date

2016-05-12

Received Date

2016-04-20

Recommended Citation

Jun-jie ZHAO, Jun CHENG. Aligning Electronic Energy Levels on the Anatase TiO₂(101) Surface[J]. Journal of Electrochemistry, 2017 , 23(1): 45-52.
DOI: 10.13208/j.electrochem.160418
Available at: https://jelectrochem.xmu.edu.cn/journal/vol23/iss1/7

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