title: [Preparation of mixed crystal TiO2 nanoparticles and photocatalytic degradation of toxic organic pollutants].
abstract: Mixed crystal TiO2 nanoparticles were prepared from a precursor of TiO2 by hydrothermal-steam method. The effects of the reaction temperature and the reaction time on the photocatalytic activity of the brookite TiO2 were studied. The TiO2 samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Photocatalytic degradation of organic dye sulforhodamine B (SRB) under UV light (lambda < or = 387 nm) was used as probe reaction to evaluate the properties of the TiO2. The result showed that TiO2 prepared under 150 degrees C for 24 h had high photocatalytic activity. The size of the mixed crystal TiO2 was 14.20 nm. Brookite and anatase phase of the mixed crystal TiO2 were 63.6% and 36.4%, respectively. The dye discoloration and degradation rates were tracked, and the intermediate products hydrogen peroxide (H2O2) and hydrogen radicals (*OH) were determined during the photocatalytic experiments. The results indicated that photocatalytic degradation of brookite TiO2 mainly referred to the *OH radical mechanism. After 5 h, the mineralization and oxidation rates of SRB and 2,4-DCP mineralization were 89% and 78%, respectively. The catalyst showed good stability with no significant changes in catalytic properties after 5 cycles of SRB photocatalytic degradation experiments.
authors.affiliation: Alan G. MacDiarmid Research Institute of Renewable Energy, Three Gorges University, Yichang 443002, China. denganping2003@126.com
authors.forename: An-Ping
authors.initials: AP
authors.lastname: Deng
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Shu-Lian
authors.initials: SL
authors.lastname: Wang
authors.forename: Ying-Ping
authors.initials: YP
authors.lastname: Huang
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
mesh_terms: D001673:Biodegradation, Environmental; D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000302:isolation & purification; D006861:Hydrogen Peroxide / Q000032:analysis; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D017382:Reactive Oxygen Species / Q000032:analysis; D012235:Rhodamines / Q000737:chemistry / Q000302:isolation & purification*; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004785:Environmental Pollutants; D005456:Fluorescent Dyes; D017382:Reactive Oxygen Species; D012235:Rhodamines; C009495:titanium dioxide; C022027:lissamine rhodamine B; D006861:Hydrogen Peroxide; D014025:Titanium