Enhancement on photocatalytic activity of an amorphous titanium oxide film with nano-textured surface by selective-fluorination etching process

Journal Article · Tue Apr 01 00:00:00 EDT 2014 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.01.023· OSTI ID:22345273

Shih, Pin-Chun; Huang, Cheng-Hao ^[1]; Chen, Tai-Hong; Lai, Li-Wen ^[2]; Lu, Yi-Shan ^[1]; Liu, Day-Shan ^[1]

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1. Institute of Electro-Optical and Materials Science, National Formosa University, Huwei, Yunlin 63201, Taiwan, ROC (China)
2. ITRI South, Industrial Technology Research Institute, Liujia, Tainan 73445, Taiwan, ROC (China)

Highlights: • The amorphous TiO{sub x} film surface was modified via selective fluorination etching process. • The resulting nano-textured surface markedly enriched the specific surface area and surface acidity. • The photocatalytic activity was comparable to an annealed TiO{sub x} film with anatase structure. - Abstract: A selective-fluorination etching process achieved by an UV light pre-irradiation and the subsequently fluorination etching was developed to enhance the photocatalytic activity of a low-temperature deposited amorphous titanium oxide (a-TiO{sub x}) film. Textured surface on the a-TiO{sub x} films formed by this process were investigated using atomic force microscope and field emission scanning electron microscope. Evidence of the fluorine ions introduced into the a-TiO{sub x} films was examined using Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy. The etching thickness of the a-TiO{sub x} film was found to be deeply relevant to the film pre-irradiated by the UV light. An a-TiO{sub x} film with nano-textured surface, which was favorable to enlarge the specific surface area, thus was obtainable from the notable etching selectivity of the film pre-irradiated by UV light through a nano-sized mask. In addition, the surface acidity of the a-TiO{sub x} film was enhanced by the formation of the Ti-F chemical bonds originating from the fluorination etching process, which also was functional to facilitate the production of surface OH free radicals. Accordingly, the resulting fluorinated a-TiO{sub x} film with nano-textured surface performed a quality photocatalytic activity comparable to that of the high-temperature achieved TiO{sub x} film with anatase structures.

• OSTI ID: 22345273
• Journal Information: Materials Research Bulletin, Vol. 52; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
DEPOSITS
ETCHING
FIELD EMISSION
FILMS
FLUORIDES
FLUORINATION
FLUORINE IONS
FOURIER TRANSFORMATION
IRRADIATION
NANOSTRUCTURES
PHOTOCATALYSIS
SCANNING ELECTRON MICROSCOPY
SURFACE PROPERTIES
TEXTURE
TITANIUM OXIDES
ULTRAVIOLET RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY