A Hybrid {Silk@Zirconium MOF} Material as Highly Efficient AsIII-sponge

Yiannis Georgiou; Sofia Rapti; Alexandra Mavrogiorgou; Gerasimos Armatas; Manolis J Manos; Maria Louloudi; Yiannis Deligiannakis

doi:10.1038/s41598-020-66091-w

A Hybrid {Silk@Zirconium MOF} Material as Highly Efficient As^III-sponge

Sci Rep. 2020 Jun 9;10(1):9358. doi: 10.1038/s41598-020-66091-w.

Authors

Yiannis Georgiou^{1

2}, Sofia Rapti¹, Alexandra Mavrogiorgou¹, Gerasimos Armatas³, Manolis J Manos^{1

4}, Maria Louloudi^{1

4}, Yiannis Deligiannakis^{5

6

7}

Affiliations

¹ Laboratory of Biomimetic Catalysis and Hybrid Materials, Department of Chemistry, University of Ioannina, GR45110, Ioannina, Greece.
² Laboratory of Physical Chemistry of Materials and Environment, Department of Physics, University of Ioannina, GR45110, Ioannina, Greece.
³ Department of Materials Science and Technology, University of Crete, Heraklion, 71003, Greece.
⁴ Institute of Materials Science and Computing, University Research Center of Ioannina, GR45110, Ioannina, Greece.
⁵ Laboratory of Physical Chemistry of Materials and Environment, Department of Physics, University of Ioannina, GR45110, Ioannina, Greece. ideligia@uoi.gr.
⁶ Institute of Materials Science and Computing, University Research Center of Ioannina, GR45110, Ioannina, Greece. ideligia@uoi.gr.
⁷ Institute of Environment & Sustainable Development, University Research Center of Ioannina, GR45110, Ioannina, Greece. ideligia@uoi.gr.

Abstract

Exposure of humans to Arsenic from groundwater drinking sources is an acute global public health problem, entailing the urgent need for highly efficient/low-cost Arsenite (As^III) up-taking materials. Herein we present an innovative hybrid-material, ZrMOF@SF_d operating like an "As^III-sponge" with unprecedented efficiency of 1800 mg As^III gr^-1. ZrMOF@SF_d consists of a neutral Zirconium Metal-Organic Framework [ZrMOF] covalently grafted on a natural silk-fiber (SF_d). ZrMOF itself exhibits As^III adsorption of 2200 mg gr^-1, which supersedes any -so far- known As^ΙΙΙ-sorbent. Using XPS, FTIR, BET-porosimetry data, together with theoretical Surface-Complexation-Modeling (SCM), we show that the high-As^ΙΙΙ-uptake is due to a sequence of two phenomena:[i] at low As^III-concentrations, surface-complexation of H₃AsO₃ results in As^III-coated voids of ZrMOF, [ii] at increased As^III-concentrations, the As^III-coated voids of ZrMOF are filled-up by H₃AsO₃ via a partitioning-like mechanism. In a more general context, the present research exemplifies a mind-changing concept, i.e. that a "partitioning-like" mechanism can be operating for adsorption of metalloids, such as H₃AsO_3, by metal oxide materials. So far, such a mechanism has been conceptualized only for the uptake of non-polar organics by natural organic matter or synthetic polymers.

Publication types

Research Support, Non-U.S. Gov't