Photoreduction and Stabilization Capability of Molecular Weight Fractionated Natural Organic Matter in Transformation of Silver Ion to Metallic Nanoparticle

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• 作者：Yongguang Yin ; Mohai Shen ; Xiaoxia Zhou ; Sujuan Yu ; Jingbo Chao ; Jingfu Liu ; Guibin Jiang
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：August 19, 2014
• 年：2014
• 卷：48
• 期：16
• 页码：9366-9373
• 全文大小：461K
• ISSN：1520-5851

文摘

Photoinduced reduction of silver ion (Ag⁺) to silver nanoparticles (AgNPs) by dissolved organic matter (DOM) plays a crucial role in the transformation and transport of engineered AgNPs and Ag⁺ in aquatic environments. DOM is a mixture of natural polymers with wide molecular weight (MW) distribution, and the roles of specific components of DOM in the photoreduction of Ag⁺ to AgNPs are still not understood. In this study, MW fractionated natural organic matter (M_f-NOM) were investigated for their roles on the photoreduction process and stabilization of the formed AgNPs. This photoinduced reduction process depends highly on pH, concentration of Ag⁺ and NOM, light quality, and the MW of M_f-NOM. Monochromatic radiation and light attenuation correction suggested that the difference of M_f-NOM on reduction was mainly ascribed to the differential light attenuation of M_f-NOM rather than the 鈥渞eal鈥?reductive ability. More importantly, compared with low MW fractions, the high MW M_f-NOMs exhibit drastically higher capability in stabilizing the photosynthesized AgNPs against Ca²⁺-induced aggregation. This finding is important for a better understanding of the differential roles of M_f-NOM in the transformation and transport of Ag⁺ and engineered AgNPs in DOM-rich surface water.