Photocatalysis by titanium dioxide and polyoxometalate/TiO2 cocatalysts. Intermediates and mechanistic study
文献类型：期刊论文
| 作者 | Chen, CC; Lei, PX; Ji, HW; Ma, WH; Zhao, JC; Hidaka, H; Serpone, N |
| 刊名 | ENVIRONMENTAL SCIENCE & TECHNOLOGY
 |
| 出版日期 | 2004 |
| 卷号 | 38期号:1页码:329-337 |
| ISSN号 | 0013-936X |
| DOI | 10.1021/es03484f |
| 英文摘要 | A representative polyoxometalate, alpha-12-tungstophosphatic acid (PW123-, POM), is loaded on the surface of TiO2 particles used as a cocatalyst to gain further insights into the underlying reaction mechanism and to estimate the feasibility of using the new POM/TiO2 cocatalyst in the photocatalytic degradation of 2,4-dichlorophenol (DCP) in aqueous media. Loading the PW123- species on the surface of TiO2 enhances charge separation in the UV-illuminated TiO2, thereby accelerating the hydroxylation of the initial DCP substrate but not the mineralization of DCP, which is somewhat suppressed in the presence of the polyoxometalate. An increase in the load of POM increases the concentration of aromatic intermediates, and more toxic intermediates, such as 2,6-dichlorodibenzo-p-dioxin, 2,4,6-trichlorophenol, are detected in the PW123-/TiO2 system. By contrast, cleavage of the whole conjugated structure of DCP predominates in TiO2 only dispersions. Strong ESR signals for the superoxide radical anionic Species, O-2(.-)(HO2. radicals in acidic media; pH < 5), are detected in TiO2 only dispersions; signals of O-2(.-) are much weaker in the TiO2/ POM composite system under otherwise identical conditions. Experimental results infers that enhancement of charge separation in TiO2 photocatalysis does not always result in improvement of the efficiency of mineralization of organic substrates, and the reaction between organic radical cations and the formed superoxide radical anions may be responsible for the mineralization of the chlorophenol. |
| 语种 | 英语 |
| WOS记录号 | WOS:000187781800059 |
| 出版者 | AMER CHEMICAL SOC |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/55769]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Zhao, JC |
| 作者单位 | 1.Chinese Acad Sci, Ctr Mol Sci, Inst Chem, Lab Photochem, Beijing 100080, Peoples R China 2.Iwaki Meisei Univ, Frontier Res Ctr Global Environm Protect, Tokyo 191, Japan 3.Concordia Univ, Dept Chem & Biochem, Montreal, PQ H3G 1M8, Canada |
| 推荐引用方式 GB/T 7714 | Chen, CC,Lei, PX,Ji, HW,et al. Photocatalysis by titanium dioxide and polyoxometalate/TiO2 cocatalysts. Intermediates and mechanistic study[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY,2004,38(1):329-337. |
| APA | Chen, CC.,Lei, PX.,Ji, HW.,Ma, WH.,Zhao, JC.,...&Serpone, N.(2004).Photocatalysis by titanium dioxide and polyoxometalate/TiO2 cocatalysts. Intermediates and mechanistic study.ENVIRONMENTAL SCIENCE & TECHNOLOGY,38(1),329-337. |
| MLA | Chen, CC,et al."Photocatalysis by titanium dioxide and polyoxometalate/TiO2 cocatalysts. Intermediates and mechanistic study".ENVIRONMENTAL SCIENCE & TECHNOLOGY 38.1(2004):329-337. |
入库方式： OAI收割
来源：化学研究所
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