Self-assembled one-dimensional MnO₂@zeolitic imidazolate framework-8 nanostructures for highly efficient arsenite removal

Abstract

a Arsenite (AsIJIII)) is more toxic and more difficult to remove from water than arsenate (AsIJV)). A pre-oxidation step is therefore necessary to achieve higher removal of AsIJIII). In this work, novel one-dimensional (1D) β-MnO 2 @ZIF-8 nanocomposites were successfully synthesized for the first time by a facile and rapid method to achieve concurrent oxidation and adsorptive removal of AsIJIII). In the synthesis step, the solution medium of methanol in the reaction plays a key role in reducing the interfacial energy and promotes the integration, leading to the deposition of ZIF-8 nanocrystals on β-MnO 2 nanowires. The synthesized β-MnO 2 @ZIF-8 exhibited a high surface area of 883 m 2 g −1. Batch experimental results showed that the as-obtained β-MnO 2 @ZIF-8 nanocomposites could oxidize AsIJIII) to AsIJV), exhibiting an improved adsorptive removal of arsenite compared to the ZIF-8 bulk. The kinetic and isotherm data of AsIJIII) adsorption on β-MnO 2 @ZIF-8 nanocomposites were well fitted by pseudo-second-order and Langmuir models, respectively. The maximal adsorption capacity of AsIJIII) was 140.27 mg g −1 at room temperature. Meanwhile, the unique 1D nanostructure of β-MnO 2 @ZIF-8 prevented ZIF-8 agglomeration in the aqueous solution. Moreover, the β-MnO 2 @ZIF-8 nanowires showed excellent settleability by gravity alone and strong mechanical stability.

MnO2‐Based Materials for Environmental Applications

“…In Zhang et al. 's work, [ 311 ] 1D β‐MnO 2 @ZIF‐8 binary heterojunctions were successfully fabricated by depositing ZIF‐8 nanocrystals on 1D β‐MnO 2 nanowires in a methanol solution (Figure 18b). In the synthesis process, the methanol solution played an important role in reducing the interface energy and promoting interface combination.…”

“…b) Reproduced with permission. [ 311 ] Copyright 2016, Royal Society of Chemistry. c) Schematic illustration of the fabrication route of α‐MnO 2 /chitosan.…”

Recent Progress in Heavy Metal Ion Decontamination Based on Metal–Organic Frameworks

“…Combining MOFs with other materials to form composites is also a method for As(III) removal. Jian et al [47] successfully synthesized novel one-dimensional (1D) β-MnO 2 @ZIF-8 nanowires (NWs) using a rapid method, achieving simultaneous oxidation and the adsorptive removal of As(III). The kinetic and isotherm data for As(III) adsorption were well fitted using the pseudo-second-order and Langmuir models, respectively.…”

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

“…Only a few reports exist on the capture of As III by MOFs 40,[43][44][45] . These sorbents, however, demonstrated only moderate sorption capacities (<150 mg As III g −1 ) 51 .…”