In-situ growth of UiO-66-NH_2 onto polyacrylamide-grafted nonwoven fabric for highly efficient Pb(Ⅱ) removal

摘要

Developing a robust and high-loading metal-organic frameworks (MOFs) composite for heavy metal removal via a facile strategy is a focus but challenging issue. Herein, a UiO-66-NH2 functionalized nonwoven fabric composite for highly efficient Pb(II) removal was developed by in-situ growth strategy. The polyethylene terephthalate (PET) nonwoven fabric support was activated by NaOH to alleviate its inertia and was further modified by polyacrylamide (PAM) to enhance its surface chemical activity to acquire PAM-PET. And then UiO-66-NH2 crystals were compactly and uniformly grown on PAM-PET surface to achieve the UiO-66-NH2-PAM-PET composite. FT-IR and XPS demonstrated the successful modification of PET surface and the facile growth of UiO-66-NH2 crystals on PAM-PET. The adsorption behavior of the UiO-66-NH2-PAM-PET composite was systematically investigated by kinetics and isotherms experiments, which respectively corresponded to the Pseudosecond-order model and the Langmuir model, indicating that the adsorption processes of this MOF composite toward Pb(II) were chemisorption and monolayer adsorption. Benefitting from the intrinsic merit of UiO-66-NH2, the UiO-66-NH2-PAM-PET composite exhibits an outstanding adsorption capacity of 711.99 mg g(-1) toward Pb(II). Furthermore, the as-prepared UiO-66-NH2-PAM-PET composite shows excellent selectivity and splendid reusability, illustrating that this MOF composite is a promising candidate to removal Pb(II) in practical applications.