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Title: Effects of peptizing conditions on nanometer properties and photocatalytic activity of TiO₂hydrosols prepared by H₂TiO₃
Authors: Liu, Tong-xu
Li, Fang-bai
Li, Xiang-zhong
Subjects: Formaldehyde
Metatitanic acid
Methyl mercaptan
Peptizing conditions
TiO2 hydrosol
Issue Date: 30-Jun-2008
Publisher: Elsevier
Source: Journal of hazardous materials, 30 June 2008, v. 155, no. 1-2, p. 90-99.
Abstract: TiO₂hydrosols were prepared from metatitanic acid (H₂TiO₃) by chemical precipitation–peptization method under various peptizing conditions. The effects of peptizing conditions on nanosized properties and photocatalytic activity of TiO₂hydrosols were investigated. The crystal structure, crystallinity, particle size distribution, and transparency (T%) of as-obtained hydrosols were characterized by means of X-ray diffraction, transmission electron microscopy, light-scattering size analyzer, and UV–vis transmittance spectra. The results showed that the properties of hydrosols depended on peptizing conditions including a molar ratio of H⁺/Ti, temperature, and solid content. The photoactivity of TiO₂hydrosols was evaluated in terms of the degradation of rhodamine B (RhB) in aqueous solution, and formaldehyde (HCHO) and methyl mercaptan (CH₃SH) in gaseous phase. The results showed that increase in H⁺/Ti ranging 0.19–0.75 led to the decrease in particle size and the increase in transparency. With increasing of temperature, particle sizes increased while the transparency and photoactivity decreased steadily when the temperature was higher than 65°C. The particle size, transparency and photoactivity of the hydrosols hardly depended on solid content when it was not less than 2%. It should be confirmed that the hydrosols with higher crystallinity, smaller particle size and higher transparency could have the higher photoactivity for the degradation of RhB, CH₃SH, and HCHO. In this study, the optimal peptizing conditions were determined to be H⁺/Ti = 0.75, temperature = 65°C and solid content = 2–6%.
Rights: Journal of Hazardous Materials © 2007 Elsevier. The journal web site is located at
Type: Journal/Magazine Article
DOI: 10.1016/j.jhazmat.2007.11.034
ISSN: 0304-3894
Appears in Collections:CEE Journal/Magazine Articles

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