Selective Adsorption of Pb2+ in the Presence of Mg2+ by Layer-by-Layer Self-Assembled MnO2/Mxene Composite Films

Abstract

A self-assembled MnO2/Mxene composite film was compounded with MXene nanosheets and layered crystalized MnO2 nanosheets using surfactant sodium dodecyl sulfate (SDS) as a soft template. The obtained material was characterized by XRD, SEM, XPS, and FT-IR, which showed that the films have large surface-active functional groups and metal ion flow channels, indicating that the MnO2/Mxene composite films were capable of both the chemical and physical adsorption of the target heavy metal ions. The analysis of adsorption performance showed that the Pb2+ removal rate reached 98.3% at pH 6 and an initial Pb2+ concentration of 30 mg/L, while the maximum adsorption capacity could reach 1235 µmol/g. In addition, the MnO2/Mxene composite film had specific selectivity and recyclability. The reuse study verified that the Pb2+ removal rate reached 96.4% after five cycles, confirming that the MnO2/Mxene composite films had practical application prospects.

MXene-based nanocomposites: emerging candidates for the removal of antibiotics, dyes, and heavy metal ions

“…Qu and his coworkers engineered self-assembled MnO 2 /MXene nanocomposite using SDS as a surfactant and functionalizing agent for the adsorption of Pb( ii ) ions. 206 Different experimental parameters were optimized for the high adsorption capacity (0.001235 mg g −1 ) at pH value 6. Therefore, the presence of transition metal oxide and surfactant agent on the surface of MXene sheets showed maximum adsorption capacity, which may provide an opportunity to eliminate Pb( ii ) ions through the electrostatic attraction of the adsorbent material with Pb 2+ ions.…”

Synthesis of Low-Crystalline MnO2/MXene Composites for Capacitive Deionization with Efficient Desalination Capacity

“…Therefore, combining the positive characteristics of MnO 2 and MXene is an effective strategy for improving the specific capacitance, rate performance, and cycle life of electrode materials. MnO 2 /Mxene composites have recently been created by numerous researchers and effectively employed in supercapacitors [30][31][32], batteries [33], catalysis [34], the removal of heavy metal ions [35,36], and other fields. However, no previous study has used MXene/MnO 2 composite materials as electrodes for achieving desalination through electrosorption.…”