Self assembled one dimensional MnO2@zeolitic imidazolate framework 8 nanostructures for highly efficient arsenite removal
Arsenite (As(III) is more toxic and more difficult to remove from water than arsenate (As(V) A pre oxidation step is therefore necessary to achieve higher removal of As(III) In this work, novel one dimensional (1D) b MnO2@ZIF 8 nanocomposites were successfully synthesized for the first time by a facile and rapid method to achieve concurrent oxidation and adsorptive removal of As(III) 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 b MnO2 nanowires. The synthesized b MnO2@ZIF 8 exhibited a high surface area of 883 m2 g 1. Batch experimental results showed that the as obtained b MnO2@ZIF 8 nanocomposites could oxidize As(III) to As(V) exhibiting an improved adsorptive removal of arsenite compared to the ZIF 8 bulk. The kinetic and isotherm data of As(III) adsorption on b MnO2@ZIF 8 nanocomposites were well fitted by pseudo second order and Langmuir models, respectively. The maximal adsorption capacity of As(III) was 140.27 mg g 1 at room temperature. Meanwhile, the unique 1D nanostructure of b MnO2@ZIF 8 prevented ZIF 8 agglomeration in the aqueous solution. Moreover, the b MnO2@ZIF 8 nanowires showed excellent settleability by gravity alone and strong mechanical stability.