Synthesis and visible-light-derived photocatalysis of titania nanosphere stacking layers prepared by chemical vapor deposition

• Published in: Journal of chemical technology and biotechnology (1986) Vol. 85; no. 8; pp. 1168 - 1174
• Main Authors: Hsieh, Chien-Te, Lai, Meng-Hsuan, Pan, Ching
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2010; Wiley
• Subjects: Applied sciences; Basic Violet 10; Catalysis; Catalytic reactions; Chemical engineering; chemical vapor deposition; Chemistry; Exact sciences and technology; General and physical chemistry; metallic doping; photocatalysis; Reactors; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; titania nanospheres; visible light; Basic Violet 10; Organic dye; Photocatalysis; Doping; Glass; Adsorption capacity; visible light; metallic doping; Density; Chemical vapor deposition; titania nanospheres; Ultraviolet radiation; Visible radiation; Light absorption; Aqueous solution; Titanium oxide; Catalyst; Crystalline structure
• ISSN: 0268-2575; 1097-4660; 1097-4660
• DOI: 10.1002/jctb.2417

BACKGROUND: In this study, visible-light-derived photocatalytic activity of metal-doped titanium dioxide nanosphere (TS) stacking layers, prepared by chemical vapor deposition (CVD), was investigated. The as-grown TS spheres, having an average diameter of 100-300 nm, formed a layer-by-layer stacking layer on a glass substrate. The crystalline structures of the TS samples were of anatase-type.RESULTS: Ultraviolet (UV) absorption confirmed that metallic doping (i.e. Co and Ni) shifted the light absorption of the spheres to the visible-light region. With increasing dopant density, the optical band gap of the nanospheres became narrower, e.g. the smallest band gap of Co-doped TS was 2.61 eV. Both Ni- and Co-doped TS catalysts showed a photocatalytic capability in decomposing organic dyes under visible irradiation. In comparison, Co-doped TiO₂ catalyst not only displays the adsorption capacity, but also the photocatalytic activity higher than the N-doped TiO₂ catalyst.CONCLUSION: This result can be attributed to the fact that the narrower band gap easily generates electron-hole pairs over the TS catalysts under visible irradiation, thus, leading to the higher photocatalytic activity. Accordingly, this study shed some light on the one-step efficient CVD approach to synthesize metal-doped TS catalysts for decomposing dye compounds in aqueous solution. Copyright