Photocatalytic Reduction of Cr(VI) in an Aqueous Suspension of Surface-Fluorinated Anatase TiO2 Nanosheets with Exposed {001} Facets

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• 作者：Zhiqiao He ; Qiaolan Cai ; Ming Wu ; Yuanqiao Shi ; Huiying Fang ; Lingdan Li ; Jiancheng Chen ; Jianmeng Chen ; Shuang Song
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：July 17, 2013
• 年：2013
• 卷：52
• 期：28
• 页码：9556-9565
• 全文大小：544K
• 年卷期：v.52,no.28(July 17, 2013)
• ISSN：1520-5045

文摘

In the present work, reduction of Cr(VI) induced by UV鈥搗isible light in aqueous solution was investigated. The aqueous medium contained TiO₂ nanosheets and no additional reducing agents or hole scavengers. A hydrothermal method was used to synthesize fluorinated TiO₂ nanostructures with various percentages of exposed {001} facets and initial F/Ti ratios. Fluorine-free TiO₂ nanosheets were obtained by washing the TiO₂ samples with NaOH solution. The surface fluorination facilitates the adsorption process by increasing the number of surface OH groups generated. Moreover, fluorination efficiently inhibits the recombination of photogenerated electron鈥揾ole pairs. The {001} facets have an indirect role in the photocatalytic reduction of Cr(VI) because oxidative dissolution of H₂O occurring on {001} facets and Cr(VI) reduction occurring on {101} facets are simultaneous reactions. The optimal ratio of exposed {001} to {101} was found to be 72:18.