Effects of nano-confinement on Zn(II) adsorption to nanoporous silica

Nelson, Joey; Bargar, John R.; Wasylenki, Laura E.; Brown, Gordon E.; Maher, Kate

doi:10.1016/j.gca.2018.08.017

Cited by 28 publications

(33 citation statements)

References 107 publications

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“…5). For comparison, the single XANES spectrum denoted as Zn sorbed to a high-surface-area amorphous silica gel by Hamilton et al (2016) more closely resembles the spectrum of willemite in their work, as well as in this study, compared with the spectra of Zn adsorbed to silica in this study, potentially attributable to the presence of a Zn silicate surface precipitate rather than an adsorbed complex on the silica gel material, which is less similar to natural silica materials than those examined herein (Nelson et al, 2017(Nelson et al, , 2018Zhuravlev, 2000).…”

Section: Zn Ads On Silicasupporting

confidence: 59%

“…In addition to establishing the presence of particular sorbed species, understanding the persistence of surface-bound metal ions in dynamic natural environments is important and related to the relationship between bond length and bond strength. The shorter bonds of tetrahedral Zn ads on silica (average Zn-O bond distance of 1.94-1.97 Å ) compared with octahedral Zn ads on silica (average Zn-O bond distance of 2.04-2.07 Å ) align with stronger binding to the surface (Nelson et al, 2017(Nelson et al, , 2018, analogous to the case of tetrahedral over octahedral triple-corner-sharing Zn surface complexes on birnessite (Kwon et al, 2009). These tetrahedral Zn ads species may therefore be less labile under changing geochemical conditions than their octahedral counterparts.…”

Section: Implications For Xanes Analysis Of Zn Ads In Other Systemsmentioning

confidence: 97%

“…Inner-sphere Zn complexation on the surface of silica has been shown to occur as a monodentate structure that locally passivates two reactive surface sites and releases two protons to maintain charge balance with the single bond of a divalent cation to the mineral surface (Nelson et al, 2018). As such, the Zn K-edge XANES spectra of tetrahedral and octahedral inner-sphere adsorption complexes at the silica-water interface portray the electronic environment of Zn with three and five water ligands, respectively, and a silica surface ligand (Zn-O-Si).…”

Section: Zn Ads On Silicamentioning

confidence: 99%

“…The propensity for transition metals, including Zn, to reside in multiple coordination environments makes aqueous, sorbed and mineral speciation complex and identification in unknown specimens challenging. Such variations in the Zn coordination environment have been documented at several mineral surfaces, including silica (Nelson et al, 2017(Nelson et al, , 2018Roberts et al, 2003), kaolinite (Guinoiseau et al, 2016;Nachtegaal & Sparks, 2004), alumina (Trainor et al, 2000;Roberts et al, 2003), montmorillonite (Lee et al, 2004), birnessite (Qin et al, 2018;Manceau et al, 2002), hematite (Ha et al, 2009), goethite (Nachtegaal & Sparks, 2004;Hamilton et al, 2016) and ferrihydrite (Waychunas et al, 2002). The precise bonding environment of Zn on mineral surfaces has implications for mobility and toxicity because different sorbed species may be differentially labile, such as octahedral versus tetrahedral Zn complexes on birnessite (Qin et al, 2018) and inner-sphere versus outer-sphere Zn complexes on hematite (Ha et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

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XANES reflects coordination change and underlying surface disorder of zinc adsorbed to silica

Nelson

2021

J Synchrotron Rad

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Zinc K-edge X-ray absorption near-edge structure (XANES) spectroscopy of Zn adsorbed to silica and Zn-bearing minerals, salts and solutions was conducted to explore how XANES spectra reflect coordination environment and disorder in the surface to which a metal ion is sorbed. Specifically, XANES spectra for five distinct Zn adsorption complexes (Znads) on quartz and amorphous silica [SiO2(am)] are presented from the Zn–water–silica surface system: outer-sphere octahedral Znads on quartz, inner-sphere octahedral Znads on quartz, inner-sphere tetrahedral Znads on quartz, inner-sphere octahedral Znads on SiO2(am) and inner-sphere tetrahedral Znads on SiO2(am). XANES spectral analysis of these complexes on quartz versus SiO2(am) reveals that normalized peak absorbance and K-edge energy position generally decrease with increasing surface disorder and decreasing Zn–O coordination. On quartz, the absorption-edge energy of Znads ranges from 9663.0 to 9664.1 eV for samples dominated by tetrahedrally versus octahedrally coordinated species, respectively. On SiO2(am), the absorption-edge energy of Znads ranges from 9662.3 to 9663.4 eV for samples dominated by tetrahedrally versus octahedrally coordinated species, respectively. On both silica substrates, octahedral Znads presents a single K-edge peak feature, whereas tetrahedral Znads presents two absorbance features. The energy space between the two absorbance peak features of the XANES K-edge of tetrahedral Znads is 2.4 eV for Zn on quartz and 3.2 eV for Zn on SiO2(am). Linear combination fitting of samples with a mixture of Znads complex types demonstrates that the XANES spectra of octahedral and tetrahedral Znads on silica are distinct enough for quantitative identification. These results suggest caution when deciphering Zn speciation in natural samples via linear combination approaches using a single Znads standard to represent sorption on a particular mineral surface. Correlation between XANES spectral features and prior extended X-ray absorption fine structure (EXAFS) derived coordination environments for these Znads on silica samples provides insight into Zn speciation in natural systems with XANES compatible Zn concentrations too low for EXAFS analysis.

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Section: Zn Ads On Silicasupporting

confidence: 59%

Section: Implications For Xanes Analysis Of Zn Ads In Other Systemsmentioning

confidence: 97%

Section: Zn Ads On Silicamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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XANES reflects coordination change and underlying surface disorder of zinc adsorbed to silica

Nelson

2021

J Synchrotron Rad

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“…The adsorption of metallic pollutants on ENPs is widely studied from different perspectives, for example from nanocatalysis [24,25], wastewater treatment [26,27] and remediation [28,29]. The most studied metal-containing ENPs include metallic ENPs, metal oxide ENPs, quantum dots (QDs) and mixtures of different ENPs.…”

Section: Adsorption Of Metallic Pollutants On Metal-containing Enpsmentioning

confidence: 99%

Effects of Mixtures of Engineered Nanoparticles and Metallic Pollutants on Aquatic Organisms

Liu

Slaveykova

2020

Environments

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In aquatic environment, engineered nanoparticles (ENPs) are present as complex mixtures with other pollutants, such as trace metals, which could result in synergism, additivity or antagonism of their combined effects. Despite the fact that the toxicity and environmental risk of the ENPs have received extensive attention in the recent years, the interactions of ENPs with other pollutants and the consequent effects on aquatic organisms represent an important challenge in (nano)ecotoxicology. The present review provides an overview of the state-of-the-art and critically discusses the existing knowledge on combined effects of mixtures of ENPs and metallic pollutants on aquatic organisms. The specific emphasis is on the adsorption of metallic pollutants on metal-containing ENPs, transformation and bioavailability of ENPs and metallic pollutants in mixtures. Antagonistic, additive and synergistic effects observed in aquatic organisms co-exposed to ENPs and metallic pollutants are discussed in the case of “particle-proof” and “particle-ingestive” organisms. This knowledge is important in developing efficient strategies for sound environmental impact assessment of mixture exposure in complex environments.

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Nanoconfinement engineering for enchanced adsorption of carbon materials, metal–organic frameworks, mesoporous silica, MXenes and porous organic polymers: a review

Zhou

2021

Environ Chem Lett

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Effects of nano-confinement on Zn(II) adsorption to nanoporous silica

Cited by 28 publications

References 107 publications

XANES reflects coordination change and underlying surface disorder of zinc adsorbed to silica

XANES reflects coordination change and underlying surface disorder of zinc adsorbed to silica

Effects of Mixtures of Engineered Nanoparticles and Metallic Pollutants on Aquatic Organisms

Nanoconfinement engineering for enchanced adsorption of carbon materials, metal–organic frameworks, mesoporous silica, MXenes and porous organic polymers: a review

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