A millimeter-sized negatively charged polymer embedded with molybdenum disulfide nanosheets for efficient removal of Pb(II) from aqueous solution

Molybdenum disulfide (MoS2) has excellent trapping ability for lead ions whereas its micro-/nanoscale size has greatly impeded its practical applications in the flow-through systems. Herein, a millimetersized nanocomposite MoS2-001 was synthesized for Pb2+ removal by loading MoS2 nanosheets into a polystyrene cation exchanger D-001 by a facile hydrothermal method. The proposed structure and adsorption mechanism of MoS2-001 was confirmed by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analysis. The nanocomposite showed outstanding adsorption capacity and rapid adsorption kinetic for Pb2+ removal, and the adsorption behavior followed the Langmuir adsorption model and pseudo-first-model kinetic model. Pb2+ uptake by MoS2-001 still maintains a high level even in the presence of extremely highly competitive ions (Ca(II) and Mg(II)), suggesting its high selectivity for Pb2+ adsorption. Besides, the fixed-bed column experiments further certified that MoS2-001 is of great potential for Pb2+ removal from the wastewater in practical engineering applications. Even more gratifying is that the exhausted MoS2-001 can be regenerated by NaCl-EDTANa(2) solution without any significant adsorption capacity loss. Consequently, all the results indicated that MoS2-001 is a promising candidate adsorbent for lead-containing wastewater treatment. (C) 2021 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

The millimeter-sized nanocomposite MoS2-001, synthesized by loading MoS2 nanosheets into a polystyrene cation exchanger, exhibits outstanding adsorption capacity and selectivity for Pb2+ removal, making it a promising candidate for lead-containing wastewater treatment in practical engineering applications.