Photocatalytic Degradation of 2-Phenethyl-2-chloroethyl Sulfide in Liquid and Gas Phases
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- 作者：Alexandre V. Vorontsov ; Alexander A. Panchenko ; Evgueni N. Savinov ; Claude Lion ; and Panagiotis G. Smirniotis
- 刊名：Environmental Science & Technology
- 出版年：2002
- 出版时间：December 1, 2002
- 年：2002
- 卷：36
- 期：23
- 页码：5261 - 5269
- 全文大小：250K
- 年卷期：v.36,no.23(December 1, 2002)
- ISSN：1520-5851
文摘
This work explores the ability of photocatalysis todecontaminate water and air from chemical warfareagent mustard using its simulant 2-phenethyl 2-chloroethylsulfide (PECES). PECES like mustard slowly dissolves inwater with hydrolysis, forming 2-phenethyl 2-hydroxyethylsulfide (PEHES). Irradiation of TiO2 suspension containingPECES with the unfiltered light of a mercury lamp (
254nm) decomposed all PECES mostly via photolysis. Reactionunder filtered light ( > 300 nm) proceeds mainlyphotocatalytically and requires longer time. Sulfur fromstarting PECES is completely transformed into sulfuric acidat the end of the reaction. Detected volatile, nonvolatile,surface products, and the suggested scheme of degradationare reported. The main volatile products are styrene andbenzaldehyde, nonvolatile - hydroxylated PEHES, surface -2-phenethyl disulfide. Photolysis of PECES produced thesame set of volatile products as photocatalysis. Photocatalyticdegradation of gaseous PECES in air results in itsmineralization but is accompanied by TiO2 deactivation.The highest rate of mineralization with minimum deactivationwas observed at about room temperature and a waterconcentration of 27 500 ppm. No gaseous products exceptCO2 were detected. The main extracted surface productwas styrene. It was concluded that PECES photocatalyticdegradation proceeds mainly via C-S bond cleavageand further oxidation of the products. Hydrolysis of theC-S bond was detected only in gas-phase photocatalyticdegradation. The quantum efficiency of gas-phasedegradation (0.28%) was much higher than that of liquid-phase degradation (0.008%). The results demonstrate theability of photocatalysis to decontaminate an aqueousand especially an air environment.
254nm) decomposed all PECES mostly via photolysis. Reactionunder filtered light ( > 300 nm) proceeds mainlyphotocatalytically and requires longer time. Sulfur fromstarting PECES is completely transformed into sulfuric acidat the end of the reaction. Detected volatile, nonvolatile,surface products, and the suggested scheme of degradationare reported. The main volatile products are styrene andbenzaldehyde, nonvolatile - hydroxylated PEHES, surface -2-phenethyl disulfide. Photolysis of PECES produced thesame set of volatile products as photocatalysis. Photocatalyticdegradation of gaseous PECES in air results in itsmineralization but is accompanied by TiO2 deactivation.The highest rate of mineralization with minimum deactivationwas observed at about room temperature and a waterconcentration of 27 500 ppm. No gaseous products exceptCO2 were detected. The main extracted surface productwas styrene. It was concluded that PECES photocatalyticdegradation proceeds mainly via C-S bond cleavageand further oxidation of the products. Hydrolysis of theC-S bond was detected only in gas-phase photocatalyticdegradation. The quantum efficiency of gas-phasedegradation (0.28%) was much higher than that of liquid-phase degradation (0.008%). The results demonstrate theability of photocatalysis to decontaminate an aqueousand especially an air environment.