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Title: A theoretical investigation on photocatalytic oxidation on the TiO{sub 2} surface

Abstract

The TiO{sub 2} photocatalytic oxidation mechanism was theoretically investigated by using long-range corrected time-dependent density functional theory (LC-TDDFT) with a cluster model of the anatase TiO{sub 2}(001) surface. We found that LC-TDDFT with the cluster model quantitatively reproduces the photoexcitations of the TiO{sub 2} surface by calculating the electronic spectra of a clean TiO{sub 2} surface and one with oxygen defects. We calculated the electronic spectra of a molecularly adsorbed TiO{sub 2} surface for the adsorptions of phenol, methanol, and methane molecules as typical organic molecules. We obtained the surprising result that the main peak of the phenol-adsorbed TiO{sub 2} surface, which overlaps with the main peak of the clean TiO{sub 2} surface, corresponds to charge transfers from the phenol molecule to the TiO{sub 2} surface. This indicates that the TiO{sub 2} photocatalytic oxidation proceeds through direct charge transfer excitation from the substrate molecules to the TiO{sub 2} surface. In contrast, we found slight and no charge transfer for methanol and methane adsorption, respectively, in agreement with the experimental findings for their reactivities. In light of these results, we propose a new mechanism for heterogeneous TiO{sub 2} photocatalytic oxidations.

Authors:
 [1]; ;  [2]
  1. Department of Applied Chemistry, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan)
  2. Advanced Science Institute, RIKEN, Wako, Saitama 351-0198 (Japan)
Publication Date:
OSTI Identifier:
22047156
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 136; Journal Issue: 2; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADSORPTION; CLUSTER MODEL; DENSITY FUNCTIONAL METHOD; METHANE; METHANOL; MOLECULES; OXIDATION; OXYGEN; PHENOL; PHOTOCATALYSIS; PHOTOCHEMISTRY; REACTION KINETICS; SEMICONDUCTOR MATERIALS; SURFACES; TITANIUM OXIDES

Citation Formats

Suzuki, Satoshi, Tsuneda, Takao, Hirao, Kimihiko, and CREST, Japan Science and Technology Agency. A theoretical investigation on photocatalytic oxidation on the TiO{sub 2} surface. United States: N. p., 2012. Web. doi:10.1063/1.3676261.
Suzuki, Satoshi, Tsuneda, Takao, Hirao, Kimihiko, & CREST, Japan Science and Technology Agency. A theoretical investigation on photocatalytic oxidation on the TiO{sub 2} surface. United States. https://doi.org/10.1063/1.3676261
Suzuki, Satoshi, Tsuneda, Takao, Hirao, Kimihiko, and CREST, Japan Science and Technology Agency. 2012. "A theoretical investigation on photocatalytic oxidation on the TiO{sub 2} surface". United States. https://doi.org/10.1063/1.3676261.
@article{osti_22047156,
title = {A theoretical investigation on photocatalytic oxidation on the TiO{sub 2} surface},
author = {Suzuki, Satoshi and Tsuneda, Takao and Hirao, Kimihiko and CREST, Japan Science and Technology Agency},
abstractNote = {The TiO{sub 2} photocatalytic oxidation mechanism was theoretically investigated by using long-range corrected time-dependent density functional theory (LC-TDDFT) with a cluster model of the anatase TiO{sub 2}(001) surface. We found that LC-TDDFT with the cluster model quantitatively reproduces the photoexcitations of the TiO{sub 2} surface by calculating the electronic spectra of a clean TiO{sub 2} surface and one with oxygen defects. We calculated the electronic spectra of a molecularly adsorbed TiO{sub 2} surface for the adsorptions of phenol, methanol, and methane molecules as typical organic molecules. We obtained the surprising result that the main peak of the phenol-adsorbed TiO{sub 2} surface, which overlaps with the main peak of the clean TiO{sub 2} surface, corresponds to charge transfers from the phenol molecule to the TiO{sub 2} surface. This indicates that the TiO{sub 2} photocatalytic oxidation proceeds through direct charge transfer excitation from the substrate molecules to the TiO{sub 2} surface. In contrast, we found slight and no charge transfer for methanol and methane adsorption, respectively, in agreement with the experimental findings for their reactivities. In light of these results, we propose a new mechanism for heterogeneous TiO{sub 2} photocatalytic oxidations.},
doi = {10.1063/1.3676261},
url = {https://www.osti.gov/biblio/22047156}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 2,
volume = 136,
place = {United States},
year = {Sat Jan 14 00:00:00 EST 2012},
month = {Sat Jan 14 00:00:00 EST 2012}
}