Novel Nanostructured Metal–Organic Framework-Bonded Silica Amine and Polymer: Facile Synthesis, Kinetics, Isotherms, and Thermodynamics Evaluation for Adsorption of Yttrium(III) Ions

Abstract

Yttrium is a remarkable rare-earth element with multidiscipline applications, and it can be released into an aquatic system for its widespread industrial applications. The present work is devoted to evaluate the kinetics and isotherm models for adsorption of Y(III) ions by the action of a novel metal–organic framework (MOF) chemically bonded polymer with incorporated ion exchange and chelating characters. To assemble these MOFs, a number of synthetic procedures were designed and performed using microwave irradiation heating in only 12 min. (i) The selected MOFs were synthesized by the reaction of zinc acetate and glutaric to produce (ZnGA) in 3 min. (ii) Covalent bonding and coating of (ZnGA) with 3-aminopropyltrimethoxysilane were carried out to produce (ZnGA–Si–NH2) in 3 min. (iii) The polymeric compound was synthesized by coupling of p-chlorocresol with piperazine via formaldehyde to yield PC in 4 min. (iv) The final MOFs–polymer nanocomposite was synthesized by the functionalization of ZnGA–Si–NH2 with PC to assemble ZnGA–Si–NH–PC in 2 min. The impact of the polymer on stability of ZnGA–Si–NH–PC in aqueous solutions (pH 1–7) was confirmed and compared to the MOFs separately. Additionally, thermal stability and surface morphology of ZnGA–Si–NH–PC were also studied and evaluated. The metal sorption capacity values of Y(III) ions onto ZnGA–Si–NH–PC were optimized at pH 7 and established as 1175, 1925, and 4800 μmol g–1 using 0.025, 0.05, and 0.1 mol L–1 of Y(III), respectively. The interaction mechanisms for binding of Y(III) ions with ZnGA–Si–NH–PC were studied and evaluated by seven kinetics models and seven adsorption isotherm models, and the collected results confirmed that the adsorption process is well fitted with the pseudo-second-order and pore diffusion models. The collected data assured that the adsorption of Y(III) ions onto the ZnGA–Si–NH–PC nanocomposite is chemisorption (ΔH° = 42.44 kJ/mol) with the direct ion exchange mechanism of Y(III) ions with the surface hydrogen ions and coordinate bond formation mechanism with the nitrogen functional groups into the available pores of the ZnGA–Si–NH–PC nanocomposite.