DOI: 10.1016/j.envpol.2019.113626
论文题名: Surface modifications at the oxide/water interface: Implications for Cu binding, solution chemistry and chemical stability of iron oxide nanoparticles
作者: Demangeat E. ; Pédrot M. ; Dia A. ; Bouhnik-Le-Coz M. ; Davranche M. ; Cabello-Hurtado F.
刊名: Environmental Pollution
ISSN: 2697491
出版年: 2020
卷: 257 语种: 英语
英文关键词: Copper speciation
; Humic acid
; Magnetite oxidation
; Phosphatidylcholine
; Surface coating
Scopus关键词: Adsorption
; Binding energy
; Binding sites
; Chemical modification
; Chemical stability
; Coatings
; Magnetite
; Magnetite nanoparticles
; Organic acids
; pH
; Sols
; Copper speciations
; Humic acid
; Magnetite oxidation
; Phosphatidylcholine
; Surface coatings
; Iron oxides
; copper
; ferric oxide
; humic acid
; magnetite nanoparticle
; phosphatidylcholine
; ultrasmall superparamagnetic iron oxide
; adsorption
; copper
; humic acid
; iron oxide
; lipid
; magnetite
; nanoparticle
; oxidation
; speciation (chemistry)
; water chemistry
; adsorption
; binding site
; complex formation
; deprotonation
; dissolution
; leaching
; oxidation
; pH
; protonation
英文摘要: The oxidation of magnetite into maghemite and its coating by natural organic constituents are common changes that affect the reactivity of iron oxide nanoparticles (IONP) in aqueous environments. Certain ubiquitous compounds such as humic acids (HA) and phosphatidylcholine (PC), displaying a high affinity for both copper (Cu) and IONP, could play a critical role in the interactions involved between both compounds. The adsorption of Cu onto four different IONP was studied: magnetite nanoparticles (magnNP), maghemite NP (maghNP), HA- and PC-coated magnetite NP (HA-magnNP and PC-magnNP, respectively). According to the results, the percentage of adsorbed Cu increases with increasing pH, irrespective of the IONP. Thus, protonation/deprotonation reactions are likely involved within Cu adsorption mechanism. Contrary to the other studied IONP, HA-magnNP favor Cu adsorption at most of the pH tested including acidic pH (pH = 3), suggesting that part of the active surface sites for Cu2+ were not grabbed by protons. The Freundlich adsorption isotherm of HA-magnNP provides the highest sorption constant KF (bonding energy) and n value which supports a heterogeneous sorption process. The heterogeneous adsorption between HA-magnNP and Cu2+ can be explained by both the diversity of the binding sites HA procured and the formation of multidendate complexes between Cu2+ and some of the HA functional groups. Such favorable adsorption process was neither observed on PC-coated-magnNP nor on maghNP, whose behaviors were comparable to that of magnNP. On another hand, HA and PC coatings considerably reduced iron (Fe) dissolution from magnNP as compared with magnNP. It was suggested that HA and PC coatings either provided efficient shield against Fe leaching or fostered dissolved Fe re-adsorption onto the functional groups at the coated magnNP surfaces. Thus, this study can help to better understand the complex interfacial reactions between cations-organic matter-colloidal surfaces which are relevant in environmental and agricultural contexts. This work showed that magnetite NP properties can be affected by surface modifications, which drive NP chemical stability and Cu adsorption, thereby affecting the global water chemistry. © 2019 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159968
Appears in Collections: 气候变化与战略
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作者单位: Univ Rennes, CNRS, Géosciences Rennes, UMR 6118, Rennes, 35000, France; Univ Rennes, CNRS, Ecobio, UMR 6553, Rennes, 35000, France
Recommended Citation:
Demangeat E.,Pédrot M.,Dia A.,et al. Surface modifications at the oxide/water interface: Implications for Cu binding, solution chemistry and chemical stability of iron oxide nanoparticles[J]. Environmental Pollution,2020-01-01,257