Exceptional As(III) Sorption Capacity by Highly Porous Magnesium Oxide Nanoflakes Made from Hydrothermal Synthesis

Authors

  • Yang Liu,

    1. Materials Center for Water Purification, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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  • Qi Li,

    Corresponding author
    1. Materials Center for Water Purification, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
      †Author to whom correspondence should be addressed. e-mail: qili@imr.ac.cn
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  • Shian Gao,

    1. Materials Center for Water Purification, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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  • Jian Ku Shang

    1. Materials Center for Water Purification, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    2. Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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  • J. Ferreira—contributing editor

  • This study was supported by the National Basic Research Program of China, Grant No. 2006CB601201, and the Knowledge Innovation Program of Institute of Metal Research, Grant No. Y0N5A111A1.

†Author to whom correspondence should be addressed. e-mail: qili@imr.ac.cn

Abstract

Highly porous magnesium oxide (MgO) nanoflakes were synthesized by the calcination of magnesium hydroxide nanoflakes created by a hydrothermal process. These MgO nanoflakes have a high specific surface area at 115.9 m2/g, and a total pore volume of ∼0.254 cm3/g. They demonstrated an exceptional As(III) removal performance from aqueous solutions, and their maximum sorption capacity could reach 506.6 mg/g, much higher than most reported values from other metal oxide nanomaterials. Such a high As(III) sorption capacity was found to depend on the in situ formation of Mg(OH)2 owing to the interaction of MgO nanoflakes with water. While preserving most of the large surface area of MgO nanoflakes, the in situ formed Mg(OH)2 had high affinity to As(III) in aqueous environment, and could react with As(III) to form a magnesium–arsenite compound, which is ultimately responsible for the exceptionally high As(III) sorption capacity of MgO nanoflakes.

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