Fabrication of Zn(II) and Cu(II) supported metal-organic frameworks for removal of some 3d metals from aqueous solutions

Abstract

Remediation of copper(II) and zinc(II) ions with the aid of metal-organic frameworks (MOFs) from its respective aqueous media was carried out. The MOFs were prepared by a solvothermal synthesis procedure of copper and zinc with benzene 1,4-dicarboxylic acid (BDC). Resultant metal-organic frameworks characterization was done with the aid of X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), energy-dispersive X-ray (EDS) spectroscopy, scanning electron microscopy (SEM), transmission electron micrograph (TEM) and pH point of zero charge (PZC). The adsorptive procedure employed to test the kinetics, equilibrium characters and thermodynamics was the batch process. Data obtained from the process were attested with the help of Temkin, Langmuir and Freundlich isotherm models; Langmuir model best fitted the data. Pseudo-first-order and pseudo-second-order rate equations were considered for kinetics. Results reveal that for copper; the metal-organic frameworks have an adsorptive capacity of 157.316 mg/g and 134.643 mg/g for Cu-BDC and Zn-BDC while the MOFs have an adsorption capacity of 145.144 mg/g and 138.158 mg/g for Cu-BDC and Zn-BDC when tested with zinc. The experimental data of the synthesized MOFs clearly indicates that they have great potential in remediating the subject metals in aqueous medium.