3D hierarchical defect-rich C@MoS2 nanosheet arrays developed on montmorillonite with enhanced performance in Pb(ii) removal

Abstract

As an emerging material for environmental remediation, MoS₂ with various dimensional nanostructures has attracted much attention. Herein, a novel C@MoS₂/montmorillonite composite material (C@MoS₂/MMT) with 3D hierarchical superstructures was successfully prepared via the facile one-step solvothermal growth of MoS₂ nanosheets with the assistance of glucose on the surface of montmorillonite (MMT). The structural analysis indicated the formation of a 3D C@MoS₂/MMT composite with C and defect-abundant MoS₂ embedded on the MMT surface with the presence of amidogen and hydroxyl groups. Consequently, the C@MoS₂/MMT composite was subjected for the removal of Pb(II) in aquatic systems and attained a maximum adsorption capacity of 187.0 mg g⁻¹ at 298 K. Additionally, the composite was found to have very high selectivity to Pb(II); it can effectively adsorb approximately 95% of Pb(II) ions in the presence of various competing ions (Cu(II), Zn(II), Cd(II) and Cr(VI)). Furthermore, the structural and morphological characteristics and possible removal mechanisms were intensively explicated in this work. The mechanism study indicated that the enhanced Pb(II) removal was due to electrostatic interactions, surface diffusion and the formation of PbMoO₄ on the surface of C@MoS₂/MMT. Therefore, this work provides a strategy for efficient environmental remediation to design hybrid nanosheets with diverse heterogeneous 3D structures using earth-abundant transition metal dichalcogenide materials and natural clay minerals.