title: Visible-light-derived photocatalyst based on TiO(2-δ)Nδ with a tubular structure.
abstract: We succeeded in achieving visible-light responsiveness on a tubular TiO(2) sample through the treatment of a tubular TiO(2) that has a large surface area with an aqueous solution of ammonia or triethylamine at room temperature and subsequent calcination at 623 K, which produced a nitrided tubular TiO(2) sample. It was found that the ease of nitridation is dependent on the surface states; washing the tubular TiO(2) sample with an aqueous acidic solution is very effective and indispensable. This treatment causes the appearance of acidic sites on the tubular TiO(2), which was proved by the following experiments: NH(3) temperature-programmed desorption and two types of organic reactions exploiting the acid properties. The prepared samples, TiO(2-δ)N(δ), efficiently absorb light in the visible region, and they exhibit a prominent feature for the decomposition of methylene blue in an aqueous solution at 300 K under irradiation with visible light, indicating the achievement of visible-light responsiveness on the tubular TiO(2) sample. This type of tubular TiO(2-δ)N(δ) sample has merit in the sense that it has a large surface area and a characteristic high transparency for enabling photocatalytic reactions because it has a tubular structure and is composed of thin walls.
authors.affiliation: Department of Fundamental Material Science, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima, Kita-ku, Okayama 700-8530, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hirose
authors.forename: Toshinori
authors.initials: T
authors.lastname: Mori
authors.forename: Yuka
authors.initials: Y
authors.lastname: Morishita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Itadani
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kudoh
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsuda
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Kittaka
authors.forename: Yasushige
authors.initials: Y
authors.lastname: Kuroda
mesh_terms: D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D008027:Light; D008751:Methylene Blue / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D055668:Photochemical Processes; D010782:Photolysis; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium; D009584:Nitrogen; D008751:Methylene Blue