Chromium speciation in Zr‐based Metal‐Organic Frameworks for environmental remediation

G. Saiz, Paula; Iglesias, Naroa; González Navarrete, Bárbara; Rosales, Maibelin; Quintero, Yurieth Marcela; Reizabal, Ander; Orive, Joseba; Fidalgo Marijuan, Arkaitz; Larrea, Edurne S.; Lopes, Catarina; Lezama, Luis; García, Andreina; Lanceros-Mendez, Senentxu; Arriortua, María Isabel; Fernandez de Luis, Roberto

Keywords: adsorption, chromium, Water remediation, Electron Paramagnetic Spectroscopy, Metal Organic Frameworks


Acute Cr VI water pollution due to anthropogenic activities is an increasing worldwide concern. The high toxicity and mobility of Cr VI makes necessary to develop dual adsorbent/ion-reductive materials that are able to capture Cr VI and transform it efficiently to less hazardous Cr III . The accurate description of the chromium speciation at the adsorbent/ion-reductive matrix is key to assess whether Cr VI is completely reduced to Cr III , or if its incomplete transformation led to the stabilization of highly reactive Cr V transient species within the material. With this goal in mind, a dual ultraviolet visible and electron paramagnetic spectroscopy approach has been applied to determine the Cr speciation within Zr-based metal-organic frameworks (MOFs). Our findings point out that the generation of defect positions at Zr-MOFs boost Cr VI adsorption, whilst the presence of reductive groups at the organic linkers play a key role to stabilize it as Cr III isolated and/or clustered ions.

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Título de la Revista: Chemistry – A European Journal
Fecha de publicación: 2020