title: A facile and versatile method for preparation of colored TiO2 with enhanced solar-driven photocatalytic activity.
abstract: Colored TiO2 has attracted enormous attention due to its visible light absorption and excellent photocatalytic activity. In this report, we develop a simple and facile solid-state chemical reduction approach for a large-scale production of colored TiO2 at mild temperature (300-350 °C). The obtained sample possesses a crystalline core/amorphous shell structure (TiO2@TiO2-x). The oxygen vacancy results in the formation of a disordered TiO2-x shell on the surface of TiO2 nanocrystals. XPS and theoretical calculation results indicate that valence band tail and vacancy band below the conduction band minimum appear for the TiO2-x, which implies that the TiO2@TiO2-x nanocrystal has a narrow band gap and therefore leads to a broad visible light absorption. Oxygen vacancy in a proper concentration promotes the charge separation of photogenerated carriers, which improves the photocatalytic activity of TiO2@TiO2-x nanocrystals. This facile and general method could be potentially used for large scale production of colored TiO2 with remarkable enhancement in the visible light absorption and solar-driven H2 production.
authors.affiliation: State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 East Nanhu Road, Changchun 130033, People's Republic of China. sunzc@ciomp.ac.cn.
authors.forename: Huaqiao
authors.initials: H
authors.lastname: Tan
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhao
authors.forename: Mang
authors.initials: M
authors.lastname: Niu
authors.forename: Chengyu
authors.initials: C
authors.lastname: Mao
authors.forename: Dapeng
authors.initials: D
authors.lastname: Cao
authors.forename: Daojian
authors.initials: D
authors.lastname: Cheng
authors.forename: Pingyun
authors.initials: P
authors.lastname: Feng
authors.forename: Zaicheng
authors.initials: Z
authors.lastname: Sun