Recyclable Nanocomposite of Flowerlike MoS<sub>2</sub>@Hybrid Acid-Doped PANI Immobilized on Porous PAN Nanofibers for the Efficient Removal of Cr(VI)

For the preparation of an ideal material for the emergency disposal of Cr­(VI)-contaminated water, a recyclable nanocomposite of molybdenum disulfide@hybrid acid-doped polyaniline immobilized on porous polyacrylonitrile nanofibers (MoS<sub>2</sub>@PANI/PAN nanocomposite) was synthesized successively through electrospinning, a hydrothermal process, and in situ polymerization. The advantages of the flowerlike MoS<sub>2</sub>@PANI/PAN nanocomposite include a fast equilibrium rate (30 min), a high removal capacity (6.57 mmol/g), and good recyclability. Thus, the material’s performance is much better than those of many earlier materials developed for similar applications. MoS<sub>2</sub>@PANI/PAN nanocomposite still showed high adsorption capacity toward Cr­(VI) in the presence of coexisting anions and natural organic matter. The remarkable interaction of this material with Cr­(VI) was shown to mainly occur through ion exchange, electrostatic adsorption, and reduction. Furthermore, the MoS<sub>2</sub>@PANI/PAN nanocomposite could be thoroughly regenerated and successfully reused for more than six cycles without a significant decrease in its removal capacity. Additional favorable properties of MoS<sub>2</sub>@PANI/PAN nanocomposite are its strong hydrophilic performance and high mechanical strength. Hence, MoS<sub>2</sub>@PANI/PAN provides a green, economic, and fast method to efficiently remove toxic Cr­(VI) from aqueous environments.