Electron-accepting potential of solvents determines photolysis rates of polycyclic aromatic hydrocarbons: Experimental and density functional theory study

论文类型：期刊论文

发表时间：2010-07-15

发表刊物：JOURNAL OF HAZARDOUS MATERIALS

收录刊物：SCIE、EI、PubMed

卷号：179

期号：1-3

页面范围：173-177

ISSN号：0304-3894

关键字：PAHs; Photodegradation; Solvent effects; Electron-accepting potential

摘要：Photochemical behaviour of polycyclic aromatic hydrocarbons (PAHs) is strongly dependent on the physical and chemical nature of the media in/on which they exist. To understand the media effects, the photolysis of phenanthrene (PHE) and benzo[a]pyrene (BaP) in several solvents was investigated. Distinct photolysis rate constants for PHE and BaP in the different solvents were observed. Some theoretical parameters reflecting the solvent properties were computed and employed to explain the solvent effects. Acetone competitively absorbed light with PHE and BaP, and the excited acetone molecules played different roles for the photodegradation of PHE and BaP. The photolysis rate constants of PHE and BaP in hexane. isopropanol, ethanol, methanol, acetonitrile and dichloromethane were observed to correlate with the electron-accepting potential of the solvent molecules. Absolute electronegativity of the solvents linearly correlated with the photolytic activity (log k) of the PAHs significantly. The results are important for better understanding the photodegradation mechanism of PAHs in different media. (C) 2010 Elsevier B.V. All rights reserved.