One-pot synthesis of multifunctional magnetic ferrite–MoS2–carbon dot nanohybrid adsorbent for efficient Pb(ii) removal

Abstract

Herein, we demonstrate a one-pot solvothermal synthetic method for fabricating MFe₂O₄ (M = Mn, Co)–MoS₂–carbon dot (CD) nanohybrid composites (MnFMC, CoFMC) with excellent Pb(II) removal ability. Detailed characterization through SEM, XRD, UV-vis spectra, fluorescence spectra and VSM confirmed the formation of the nanohybrid composites. The adsorption behavior of the as-prepared nanohybrids was systematically studied using kinetic and equilibrium experiments, and the adsorption mechanism was further revealed using XPS and FTIR. Taking advantage of the cation substitution of abundant functional groups on the surface of CDs and MFe₂O₄ nanoparticles, as well as the large surface of available MoS₂ for enhancing the sequestration of target metal-pollutants, the as-prepared composites exhibit high adsorption performances (588.24 mg g⁻¹ for MnFMC and 660.67 mg g⁻¹ for CoFMC) and show preferential Pb(II) sorption behavior with a high level concentration of competing cations (Ca(II)/Mg(II)). Moreover, these nanohybrid adsorbents exhibit excellent reusability, lower the effluent Pb(II) contents down to the ppb level, which satisfies the drinking water standard recommended by the World Health Organization, and are promising candidates for water purification.