Self-assembly regulation of montmorillonite nanosheet for Pb(II) removal from aqueous solution

L-cysteine (Lcys) induced the self-assembly of montmorillonite nanosheets (MMTNS), creating a threedimensional structured adsorbent with high adsorption capacity for Pb(II). Lcys was grafted onto the edge of MMTNS by hydrogen-bonding and then formed disulfide bonds (-S-S-) under the oxidation of H2O2 to form MMTNS-Lcys adsorbent. This technique maintains the exposed adsorption sites of MMTNS and resolves the challenge of nanosheet separation from water. MMTNS-Lcys possessed a large specific surface area (73.95 m2 g-1) and pore volume (0.1124 cm3 g-1), exhibiting outstanding adsorption performance for Pb(II), The adsorption process is consistent with the Pseudo-first-order kinetic and Langmuir isotherm models, indicating the monolayer adsorption of Pb(II) on the homogeneous surface of the MMTNS-Lcys adsorbent, with a maximum adsorption capacity of 46.92 mg/g (C0 = 80 mg/L, M = 0.5 g/L, T = 25 degrees C, pH = 6). These findings offer valuable insights for the design and development of future adsorbent materials.

Automated summary

Translation: L-cysteine induces the self-assembly of montmorillonite nanosheets, creating a structured adsorbent with high adsorption capacity for Pb(II). The adsorbent maintains the exposed adsorption sites and solves the challenge of nanosheet separation from water. The findings provide valuable insights for the design and development of future adsorbent materials.