Effective Enhancement of the Degradation of Oxalic Acid by Catalytic Ozonation with TiO2 by Exposure of {001} Facets and Surface Fluorination

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• 作者：Zhiqiao He ; Qiaolan Cai ; Fangyue Hong ; Zhe Jiang ; Jianmeng Chen ; Shuang Song
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：April 25, 2012
• 年：2012
• 卷：51
• 期：16
• 页码：5662-5668
• 全文大小：407K
• 年卷期：v.51,no.16(April 25, 2012)
• ISSN：1520-5045

文摘

Heterogeneous catalytic ozonation is a promising advanced oxidation technology for water treatment. In the present work, the surface fluorination of TiO₂ catalysts with a high percentage of exposed {001} facets (F-TiO₂) were synthesized through a hydrothermal method using tetrabutyl titanate as the precursor and HF as the shape controlling agent. The structural properties of the catalysts were characterized by X-ray diffraction, the Brunauer鈥揈mmett鈥揟eller method, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The sheetlike TiO₂ is pure anatase, with 75% of highly reactive {001} facets. The surface fluoride of the F-TiO₂ nanosheets can be removed by washing with dilute NaOH solution (abbreviated here as OH-TiO₂), resulting in a decrease of Ti³⁺ content and an increase of the specific surface area. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. It was found that F-TiO₂ facilitated the catalytic ozonation process by comparison with OH-TiO₂ and pure TiO₂ nanoparticles prepared in pure water. We conclude that the high surface energies of {001} facets and the increased concentration of oxygen vacancies contributed to the enhancement of the ozonation activity of fluorinated TiO₂ with dominant {001} facets.