In this study, a nanocomposite aerogel based on cotton linter, carbon nanotubes (CNTs), an‎d ZIF-67 was synthesized via a sol–gel method for the removal of Pb²⁺ heavy metal ions from aqueous solutions. The prepared nanocomposite was characterized using various techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), an‎d X-ray elemental mapping (MAP). The FT-IR results confirmed the presence of characteristic functional groups of each composite component, an‎d all the distinctive peaks of cotton linter, CNTs, an‎d ZIF-67 were observed in the composite spectrum. FE-SEM images revealed the presence of the well-defined polyhedral structure of ZIF-67, uniform dispersion of CNTs, an‎d the porous fibrous texture of cotton linter within the aerogel matrix. In the XRD analysis, due to the very low content of ZIF-67 an‎d CNTs in the final structure, their characteristic peaks were barely detectable; however, other analyses confirmed their presence within the aerogel. The results demonstrated that incorporating different percentages of CNTs an‎d ZIF-67 significantly enhanced the adsorption efficiency. Experimental investigations showed that using only 15 mg of the cotton linter/CNTs/ZIF-67 nanocomposite aerogel, a lead ion removal efficiency of 50% was achieved within a short time of 30 minutes. This excellent performance can be attributed to the aerogel’s porous structure, increased effective contact surface area, an‎d synergistic effects arising from the simultaneous presence of CNTs an‎d ZIF-67. Furthermore, equilibrium adsorption data were fitted to eight different isotherm models, an‎d the results indicated that the adsorption process was physical, multilayered, an‎d occurred on heterogeneous energy surfaces, fitting well with multilayer isotherm models such as the Khan model. The findings suggest that the synthesized nanocomposite aerogel can serve as an efficient, stable, an‎d eco-friendly adsorbent for removing metal contaminants from water, offering a promising alternative to traditional water purification methods.

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وحيد صباغي

كيومرث زرگوش , كاظم كرمي