Photocatalytic Degradation of Commercial Phoxim over La-Doped TiO2 Nanoparticles in Aqueous Suspension

被引：87

作者：

Dai, Ke ^{[1
]}

Peng, Tianyou ^{[1
]}

Chen, Hao ^{[2
]}

Liu, Juan ^{[2
]}

Zan, Lin ^{[1
]}

机构：

[1] Wuhan Univ, Coll Chem & Mol Sci, Wuhan 430072, Peoples R China

[2] Huazhong Agr Univ, Coll Sci, Wuhan 430070, Peoples R China

来源：

ENVIRONMENTAL SCIENCE & TECHNOLOGY | 2009年 / 43卷 / 05期

关键词：

TITANIUM-DIOXIDE; MINERALIZATION; ACIDS;

D O I：

10.1021/es802724q

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Photocatalytic degradation of commercial phoxim emulsion in aqueous suspension was investigated by using La-doped mesoporous TiO2 nanoparticles (m-TiO2) as the photocatalyst under UV irradiation. Effects of La-doping level, calcination temperature, and additional amount of the photocatalyst on the photocatalytic degradation efficiency were investigated in detail. Experimental results indicate that 20 mg L-1 phoxim in 0.5 g L-1 La/m-TiO2 suspension (the initial pH 4.43) can be decomposed as prolonging the irradiation time. Almost 100% phoxim was decomposed after 4 h irradiation according to the spectrophotometric analyses, whereas the mineralization rate of phoxim just reached ca. 80% as checked by ion chromatography (IC) analyses. The elimination of the organic solvent in the phoxim emulsion as well as the formation and decomposition of some degradation intermediates were observed by high-performance liquid chromatography-mass spectroscopy (HPLC-MS). On the basis of the analysis results on the photocatalytic degradation intermediates, two possible photocatalytic degradation pathways are proposed under the present experimental conditions, which reveal that both the hydrolysis and adsorption of phoxim under UV light irradiation play important roles during the photocatalytic degradation of phoxim.

引用

页码：1540 / 1545

页数：6

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