Sputtering pressure dependent photocatalytic properties of TiO{sub 2} thin films

Journal Article · Sat Jul 15 04:00:00 EDT 2006 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2187984· OSTI ID:20777312

Takahashi, T; Prabakar, K; Nezuka, T; Yamazaki, T; Nakashima, T; Kubota, Y; Fujishima, A ^[1]

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1. Department of Electrical and Electronic Engineering, Faculty of Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

The TiO{sub 2} films were deposited on glass substrate by direct current reactive magnetron sputtering under various total sputtering gas pressures (P{sub Tot}) of 0.2, 0.5, 0.8, and 5 Pa and at the target to substrate distances (D{sub T-S}) of 40 and 70 mm. Argon and oxygen gas mixtures (Ar:O{sub 2}=80:20) were used to deposit the films. The optimum conditions to deposit the films with high photocatalytic activities were investigated in detail using in situ Fourier transform infrared spectra in relation to the sputter deposition processes. The band gap energy was found to decrease from 3.25 to 3.13 eV for the TiO{sub 2} films deposited at P{sub Tot} of 5-0.2 Pa and D{sub T-S} of 40 mm. For the films deposited at D{sub T-S} of 70 mm, the band gap varied between 3.3 and 3.2 eV. The rate of decomposition of methanol is rapid for the films deposited at P{sub Tot} of 0.2 Pa and D{sub T-S} of 40 mm and as the D{sub T-S} and P{sub Tot} increase, the photo-oxidation of methanol by TiO{sub 2} decreases. The formaldehyde and CO species are the main intermediates by increasing the irradiation time and CO{sub 2} is produced after the complete decomposition.

• OSTI ID: 20777312
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 4 Vol. 24; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARGON
CARBON DIOXIDE
CARBON MONOXIDE
DECOMPOSITION
FORMALDEHYDE
FOURIER TRANSFORMATION
INFRARED SPECTRA
METHANOL
PRESSURE DEPENDENCE
SEMICONDUCTOR MATERIALS
SPUTTERING
SUBSTRATES
THIN FILMS
TITANIUM OXIDES