Pristine ɣ-Fe2O3 nanoparticles, called surface active maghemite nanoparticles (SAMNs) display unprecedented colloidal stability and specific binding properties. Herein, the interactions of SAMNs with AsV and AsIII as surface molecular probes were comparatively studied. Thermodynamic and kinetic characterizations, along with chemical and structural analysis of SAMN@As complexes, evidenced two distinct binding modalities. Arsenite, emerged as an elective and specific ligand for SAMNs, whereas arsenate adsorption was more labile, pH dependent and ruled by different binding possibilities. In particular, AsIII oxyacid exclusively interacts through inner-sphere coordination occupying available surface crystal positions resembling a key-lock fitting, while AsV leads to both outer-sphere and inner-sphere complexes. Noteworthy, discrimination between AsV and AsIII was never reported for nanostructured maghemite evidencing the importance of synthetic route on surface properties of the nanomaterial. The present report, besides enriching the chemistry of nanosized iron oxides, suggests SAMNs application for the remediation of water contaminated by AsIII, the most threatening As species in water.

Smart synthetic maghemite nanoparticles with unique surface properties encode binding specificity toward AsIII

Molinari, Simone
Membro del Collaboration Group
;
Magro, Massimiliano
Membro del Collaboration Group
;
Baratella, Davide
Membro del Collaboration Group
;
Salviulo, Gabriella
Supervision
;
Vianello, Fabio
Project Administration
2020

Abstract

Pristine ɣ-Fe2O3 nanoparticles, called surface active maghemite nanoparticles (SAMNs) display unprecedented colloidal stability and specific binding properties. Herein, the interactions of SAMNs with AsV and AsIII as surface molecular probes were comparatively studied. Thermodynamic and kinetic characterizations, along with chemical and structural analysis of SAMN@As complexes, evidenced two distinct binding modalities. Arsenite, emerged as an elective and specific ligand for SAMNs, whereas arsenate adsorption was more labile, pH dependent and ruled by different binding possibilities. In particular, AsIII oxyacid exclusively interacts through inner-sphere coordination occupying available surface crystal positions resembling a key-lock fitting, while AsV leads to both outer-sphere and inner-sphere complexes. Noteworthy, discrimination between AsV and AsIII was never reported for nanostructured maghemite evidencing the importance of synthetic route on surface properties of the nanomaterial. The present report, besides enriching the chemistry of nanosized iron oxides, suggests SAMNs application for the remediation of water contaminated by AsIII, the most threatening As species in water.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3347541
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 7
  • ???jsp.display-item.citation.isi??? 7
social impact