Abstract
Chromium (VI) and arsenic (V) oxoanions are major toxic heavy metal pollutants in water threatening both human health and environmental safety. Herein, the development is reported of a bifunctional ionic covalent organic network (iCON) with integrated guanidinium and phenol units to simultaneously sequester chromate and arsenate in water via a synergistic ion-exchange-redox process. The guanidinium groups facilitate the ion-exchange-based adsorption of chromate and arsenate at neutral pH with fast kinetics and high uptake capacity, whereas the integrated phenol motifs mediate the Cr(VI)/Cr(III) redox process that immobilizes chromate and promotes the adsorption of arsenate via the formation of Cr(III)-As(V) cluster/complex. The synergistic ion-exchange-redox approach not only pushes high adsorption efficiency for both chromate and arsenate but also upholds a balanced Cr/As uptake ratio regardless of the change in concentration and the presence of interfering oxoanions.
Original language | English |
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Article number | 2104703 |
Journal | Small |
Volume | 17 |
Issue number | 46 |
DOIs | |
State | Published - Nov 18 2021 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. The computational study is this work used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy (DOE) under Contracts No. DE-AC05-00OR22725. XPS measurements were supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The authors also thank Particle Testing Authority, Micromeritics Inc. Georgia for the help in measuring the specific surface area of the materials. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. The computational study is this work used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy (DOE) under Contracts No. DE‐AC05‐00OR22725. XPS measurements were supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering. This manuscript has been authored by UT‐Battelle, LLC, under contract DE‐AC05‐00OR22725 with the US Department of Energy (DOE). The authors also thank Particle Testing Authority, Micromeritics Inc. Georgia for the help in measuring the specific surface area of the materials.
Keywords
- arsenate
- chromate
- covalent organic networks
- ion exchange
- oxoanion sequestration
- redox process