Interfacial growth of nitrogen-doped carbon with multi-functional groups on the MoS2 skeleton for efficient Pb(II) removal

Highlights: • Two-dimensional NC-MoS₂ was synthesized by a facile solvothermal method. • Nitrogen-doped carbons possess abundant functional groups for heavy metal removal. • NC-MoS₂ possesses an excellent adsorption capacity (439.09 mg g⁻¹) for Pb(II). • Inner-sphere complex formation and ion-exchange process control Pb(II) adsorption. • NC-MoS₂ can be reused for seven cycles with great potential for water purification. Lead(II) is a highly toxic upon accumulation in the human body and a thorough cleanup of this pollutant in water resources has become a rising worldwide concern. In this study, multi-functional nitrogen-doped carbon-MoS₂ (NC-MoS₂) nanohybrid composite was successfully synthesized by a step-by-step approach and applied as an effective heavy metal ions adsorbent. Scanning electron microscopy and energy dispersive X-ray spectrometer analysis presents multilayer irregular nanosheets and reveals the uniform distribution of C, N and O elements in the fabricated nanomaterials, respectively. Powder X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the functionalization of oxygen-containing functional groups arising from the nitrogen-doped carbon. Particularly, the NC-MoS₂ possesses an excellent adsorption capacity (439.09 mg g⁻¹) for Pb(II), which attributes to the integrated physicochemical adsorption resulting from the oxygen-containing functional groups on the surface of nanohybrid composites. The as-prepared NC-MoS₂ exhibits good chemical stability and can be reused 7 times with a slight fading over 80% during cycling, which is essential for its practical applications. All of these demonstrate that NC-MoS₂ can be an efficient material for selectively removal of Pb(II), which suggest its great potential in the utilization of environmental cleanup.