Investigation of photocatalytic activity of TiO{sub 2}/WO{sub 3} bilayered thin films with various amounts of WO{sub 3} exposed surface

Journal Article · Wed Jul 15 00:00:00 EDT 2009 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3086647· OSTI ID:22053512

Biswas, S; Hossain, M F; Shahjahan, M; Takahashi, K; Takahashi, T; Fujishima, A ^[1]

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1. Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

Transparent WO{sub 3}/TiO{sub 2} bilayered thin films were deposited on glass substrates by facing target sputtering technique with different amounts of WO{sub 3} exposed surface (0%, 30%, 50%, 80%, and 100%) to study the separate role of WO{sub 3} and TiO{sub 2} in the photocatalytic activity of the composite system. The crystallographic and optical properties of WO{sub 3} and the TiO{sub 2} layers were investigated in detail. The photocatalytic activity was evaluated by the measurement of decomposition of methanol in gas phase under visible light irradiation with very little ultraviolet content. The rate of decomposition of gaseous methanol largely depends on the ratio of WO{sub 3}/TiO{sub 2} exposed surface. The decomposition efficiency of WO{sub 3}/TiO{sub 2} films increased with an increase in TiO{sub 2} exposed surface and the sample with 70%TiO{sub 2} exposed area showed the highest efficiency. The surface morphology of all the layers was investigated by the measurement of field emission scanning electron microscope and atomic force microscope. The variation in photocatalytic activity has been tried to be explained on the basis of methanol-photodecomposition mechanism and the intrinsic properties of WO{sub 3} and TiO{sub 2} semiconductor.

• OSTI ID: 22053512
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 27, Issue 4; Other Information: (c) 2009 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ATOMIC FORCE MICROSCOPY
DECOMPOSITION
FIELD EMISSION
METHANOL
MORPHOLOGY
OPTICAL PROPERTIES
PHOTOCATALYSIS
RADIATION EFFECTS
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SPUTTERING
SUBSTRATES
SURFACES
THIN FILMS
TITANIUM OXIDES
TUNGSTEN OXIDES
ULTRAVIOLET RADIATION
VISIBLE RADIATION