Characterization and photocatalytic activity of Fe- and N-co-deposited TiO{sub 2} and first-principles study for electronic structure

Journal Article · Mon Aug 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.05.036· OSTI ID:21580189

Yen, Chung-Chih ^[1]; Wang, Da-Yung ^[2]; Chang, Li-Shin ^[1]

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1. Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40249, Taiwan (China)
2. Department of Materials Science and Engineering, MingDao University, 369 Wen-Hua Road, Changhua 52345, Taiwan (China)

Titanium dioxide (TiO{sub 2}), co-deposited with Fe and N, is first implanted with Fe by a metal plasma ion implantation (MPII) process and then annealed in N{sub 2} atmosphere at a temperature regime of 400-600 deg. C. First-principle calculations show that the (Fe, N) co-deposited TiO{sub 2} films produced additional band gap levels at the bottom of the conduction band (CB) and on the top of the valence band (VB). The (Fe, N) co-deposited TiO{sub 2} films were effective in both prohibiting electron-hole recombination and generating additional Fe-O and N-Ti-O impurity levels for the TiO{sub 2} band gap. The (Fe, N) co-deposited TiO{sub 2} has a narrower band gap of 1.97 eV than Fe-implanted TiO{sub 2} (3.14 eV) and N-doped TiO{sub 2} (2.16 eV). A significant reduction of TiO{sub 2} band gap energy from 3.22 to 1.97 eV was achieved, which resulted in the extension of photocatalytic activity of TiO{sub 2} from UV to Vis regime. The photocatalytic activity and removal rate were approximately two-fold higher than that of the Fe-implanted TiO{sub 2} under visible light irradiation. - Graphical abstract: The electronic properties of (Fe, N) co-deposited TiO{sub 2} films determined by theoretical calculations is graphically shown; Fe and N preferentially substitute the Ti and O site, to form impurity level. Highlights: > The MPII produces a simple and low cost process for the fabrication of visible light photocatalysts. > Both theoretical and experimental approaches are used to discuss the relationship between band structure and photocatalysis. > The Fe and N preferentially substitute the Ti and O site, which generate additional Fe-O and N-Ti-O impurity levels for the TiO{sub 2} band gap. > A significant reduction of TiO{sub 2} band gap energy from 3.22 to 1.97 eV was achieved.

• OSTI ID: 21580189
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 8; Other Information: DOI: 10.1016/j.jssc.2011.05.036; PII: S0022-4596(11)00285-4; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DEPOSITION
DOPED MATERIALS
ELECTRONIC STRUCTURE
FILMS
IMPURITIES
ION IMPLANTATION
IRRADIATION
PHOTOCATALYSIS
PLASMA
TITANIUM OXIDES
VISIBLE RADIATION
CATALYSIS
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
MATERIALS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS