Stability of silver nanoparticle sulfidation products
Stability of silver nanoparticle sulfidation products
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DOI：
10.1016/j.scitotenv.2018.08.239
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发表时间：
2019-01-15
影响因子：
9.8
通讯作者：
Mullaugh, Katherine M.
中科院分区：
文献类型：
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作者：
Fletcher, Nathaniel D.;Lieb, Heather C.;Mullaugh, Katherine M.
消费品中银纳米颗粒的采用引起了人们对其广泛使用可能造成的环境危害的担忧。我们研究了Ag NPs在通过废水处理厂（WWTP）中常见的富含硫化物的条件时可能发生的化学转化，这可能会由于形成低溶解度的硫化银（Ag2S）而限制Ag NPs中Ag+的释放。然而，尚不确定硫化是否完全以及硫化的Ag NPs是否继续释放Ag+。为了解决这些不确定性，我们在两个月的时间里用离子选择性电极和紫外/可见分光光度法监测了银纳米粒子与不同水平的硫化物的反应。我们通过吹扫捕集酸性挥发性硫化物 (AVS) 分析来表征硫化反应的产物，该分析可作为硫化产物稳定性的衡量标准，因为除非以 Ag2S 的形式稳定，否则硫化物很容易因氧化而损失。 Ag NP 表面等离子共振 (SPR) 吸收峰最初减弱，然后在与有限量的硫化物反应后几天内恢复，表明动态系统可能保留原始 Ag NP 的一些特性。然而，两个月内对硫化银纳米粒子悬浮液进行的 ICP-MS 分析表明，即使硫化物浓度相对于银而言有限，硫化也限制了通过 WWIP 的纳米银中 Ag+ 离子的释放。 (C) 2018 Elsevier B.V. 保留所有权利。
The adoption of silver nanopartides in consumer goods has raised concerns about the potential environmental harm of their widespread use. We studied chemical transformations that Ag NPs may undergo as they pass through sulfide-rich conditions common in waste water treatment plants (WWTPs), which may limit the release of Ag+ from Ag NPs due to the formation of low-solubility silver sulfide (Ag2S). However, it is uncertain whether sulfidation is complete and if sulfidized Ag NPs continue to release Ag+. To address these uncertainties, we monitored the reaction of Ag NPs with various levels of sulfide with an ion selective electrode and UV/visible spectrophotometry over the course of two months. We characterized the products of the sulfidation reactions with a purge-and-trap acid volatile sulfide (AVS) analysis, which served as a measure of the stability of the sulfidized products because sulfide would be readily lost to oxidation unless it is stabilized as Ag2S. The Ag NP surface plasmon resonance (SPR) absorbance peak was initially diminished and then returned over the course of several days after reaction with limited amounts of sulfide, suggesting a dynamic system that may retain some characteristics of the pristine Ag NPs. However, ICP-MS analysis of sulfidized Ag NP suspensions over a two-month period demonstrates that sulfidation limits the release of Ag+ ions from nanosilver that pass through a WWIP, even when sulfide concentrations are limited relative to silver. (C) 2018 Elsevier B.V. All rights reserved.