Enhanced Photocatalytic Degradation and Selective Removal of Nitrophenols by Using Surface Molecular Imprinted Titania
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- 作者：Xiantao Shen ; Lihua Zhu ; Guoxia Liu ; Hongwei Yu ; Heqing Tang
- 刊名：Environmental Science & Technology
- 出版年：2008
- 出版时间：March 1, 2008
- 年：2008
- 卷：42
- 期：5
- 页码：1687 - 1692
- 全文大小：459K
- 年卷期：v.42,no.5(March 1, 2008)
- ISSN：1520-5851
文摘
Poor selectivity of titania (TiO2) photocatalysis is unfavorable to photocatalytic removal of highly toxic low-level organic pollutants in polluted waters in the presence of other less toxic high-level pollutants. A new strategy of increasing this selectivity is the surface modification of TiO2 via coating a thin layer of molecular imprinted polymer (MIP), which provides molecular recognition ability toward the template molecules. By using 2-nitrophenol and 4-nitrophenol as target pollutants, MIP-coated TiO2 photocatalysts were prepared via surface molecular imprinting and were observed to have high activity and selectivity toward the photodegradation of the targets. In the presence of bisphenol A (50 mg L−1) as a nontarget pollutant, the apparent rate constant for the photodegradation of the target 2-nitrophenol and 4-nitrophenol (1.8 mg L−1) over the corresponding MIP-coated TiO2 was 10.73 × 10−3 and 7.06 × 10−3 min−1, being 2.46 and 4.61 times of that (4.36 × 10−3 and 1.53 × 10−3 min−1) over neat TiO2, respectively. The enhanced photocatalytic selectivity was increased when the concentration of the target was decreased and/or when the difference in both the chemical structure and molecule size between the target and nontarget molecules was increased. The increased selectivity was mainly attributed to the special interaction between the target molecules and the footprints polymer via the functional groups (-OH and -NO2).