Sulfidation processes of PVP-coated silver nanoparticles in aqueous solution: impact on dissolution rate

TitleSulfidation processes of PVP-coated silver nanoparticles in aqueous solution: impact on dissolution rate
Publication TypeJournal Article
Year of Publication2011
AuthorsLevard C, Reinsch BC, Michel FM, Oumahi C, Lowry GV, Brown, Jr GE
JournalEnvironmental Science & Technology
Volume45
Pagination5260-5266
ISBN Number0013-936X
Abstract

Despite the increasing use of silver nanoparticles (Ag-NPs) in nanotechnology and their toxicity to invertebrates, the transformations and fate of Ag-NPs in the environment are poorly understood. This work focuses on the sulfidation processes of PVP-coated Ag-NPs, one of the most likely corrosion phenomena that may happen in the environment. The sulfur to Ag-NPs ratio was varied in order to control the extent of Ag-NPs transformation to silver sulfide (Ag(2)S). A combination of synchrotron-based X-ray Diffraction (XRD) and Extended X-ray Absorption Fine Structure spectroscopy shows the increasing formation of Ag(2)S with an increasing sulfur to Ag-NPs ratio. TEM observations show that Ag(2)S forms nanobridges between the Ag-NPs leading to chain-like structures. In addition, sulfidation strongly affects surface properties of the Ag-NPs in terms of surface charge and dissolution rate. Both may affect the reactivity, transport, and toxicity of Ag-NPs in soils. In particular, the decrease of dissolution rate as a function of sulfide exposure may strongly limit Ag-NPs toxicity since released Ag(+) ions are known to be a major factor in the toxicity of Ag-NPs.

URLhttp://pubs.acs.org/doi/abs/10.1021/es2007758