Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure
Nanoscale zerovalent iron (nZVI) particles were successfully employed for Cr(VI) removal from aqueous solutions at pH 3. It was found that the capacity of the system increases with increasing nZVI dosage. Starting at 300. μM, a complete Cr(VI) conversion was achieved in 30. min with a Fe:Cr(VI) mola...
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todo:paper_13858947_v244_n_p569_NahuelMontesinos2023-10-03T16:12:13Z Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure Nahuel Montesinos, V. Quici, N. Beatriz Halac, E. Leyva, A.G. Custo, G. Bengio, S. Zampieri, G. Litter, M.I. Hexavalent chromium Nanoscale zerovalent iron Raman spectroscopy XPS analysis Nanoscale zerovalent iron (nZVI) particles were successfully employed for Cr(VI) removal from aqueous solutions at pH 3. It was found that the capacity of the system increases with increasing nZVI dosage. Starting at 300. μM, a complete Cr(VI) conversion was achieved in 30. min with a Fe:Cr(VI) molar ratio (MR) of 3, and 45% conversion with MR= 1 over the same period of time. The material exhibited an enhanced reactivity in comparison with other previously tested similar materials. The proposed mechanism involves an initial reduction of Cr(VI) to Cr(III) by reaction with Fe0 or Fe(II) on the particle surface or in solution (secondary pathway), followed by an arrest on Cr(VI) removal attributed to the passivation of the surface of the nanoparticles. Passivation was confirmed by Raman and X-ray photoelectron spectroscopies (XPS). Furthermore, XPS analysis demonstrated that Cr(III) is the only Cr species present in the external layer of the nanoparticles after the reaction. Raman analysis and XPS measurements performed after mild sputtering showed that nZVI exposed to Cr(VI) presented a structure, from outside to inside, of hydroxychromites→magnetite→Fe0. © 2014 Elsevier B.V. Fil:Litter, M.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_13858947_v244_n_p569_NahuelMontesinos |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Hexavalent chromium Nanoscale zerovalent iron Raman spectroscopy XPS analysis |
| spellingShingle |
Hexavalent chromium Nanoscale zerovalent iron Raman spectroscopy XPS analysis Nahuel Montesinos, V. Quici, N. Beatriz Halac, E. Leyva, A.G. Custo, G. Bengio, S. Zampieri, G. Litter, M.I. Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| topic_facet |
Hexavalent chromium Nanoscale zerovalent iron Raman spectroscopy XPS analysis |
| description |
Nanoscale zerovalent iron (nZVI) particles were successfully employed for Cr(VI) removal from aqueous solutions at pH 3. It was found that the capacity of the system increases with increasing nZVI dosage. Starting at 300. μM, a complete Cr(VI) conversion was achieved in 30. min with a Fe:Cr(VI) molar ratio (MR) of 3, and 45% conversion with MR= 1 over the same period of time. The material exhibited an enhanced reactivity in comparison with other previously tested similar materials. The proposed mechanism involves an initial reduction of Cr(VI) to Cr(III) by reaction with Fe0 or Fe(II) on the particle surface or in solution (secondary pathway), followed by an arrest on Cr(VI) removal attributed to the passivation of the surface of the nanoparticles. Passivation was confirmed by Raman and X-ray photoelectron spectroscopies (XPS). Furthermore, XPS analysis demonstrated that Cr(III) is the only Cr species present in the external layer of the nanoparticles after the reaction. Raman analysis and XPS measurements performed after mild sputtering showed that nZVI exposed to Cr(VI) presented a structure, from outside to inside, of hydroxychromites→magnetite→Fe0. © 2014 Elsevier B.V. |
| format |
JOUR |
| author |
Nahuel Montesinos, V. Quici, N. Beatriz Halac, E. Leyva, A.G. Custo, G. Bengio, S. Zampieri, G. Litter, M.I. |
| author_facet |
Nahuel Montesinos, V. Quici, N. Beatriz Halac, E. Leyva, A.G. Custo, G. Bengio, S. Zampieri, G. Litter, M.I. |
| author_sort |
Nahuel Montesinos, V. |
| title |
Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| title_short |
Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| title_full |
Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| title_fullStr |
Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| title_full_unstemmed |
Highly efficient removal of Cr(VI) from water with nanoparticulated zerovalent iron: Understanding the Fe(III)-Cr(III) passive outer layer structure |
| title_sort |
highly efficient removal of cr(vi) from water with nanoparticulated zerovalent iron: understanding the fe(iii)-cr(iii) passive outer layer structure |
| url |
http://hdl.handle.net/20.500.12110/paper_13858947_v244_n_p569_NahuelMontesinos |
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