Lanthanide metal–organic frameworks as selective microporous materials for adsorption of heavy metal ions

Abstract

Four microporous lanthanide metal-organic frameworks (MOFs), namely Ln(BTC)(H2O)(DMF)1.1 (Ln = Tb, Dy, Er and Yb, DMF = dimethylformamide, H3BTC = benzene-1,3,5-tricarboxylic acid), have been used for selective adsorption of Pb(ii) and Cu(ii). Among these MOFs, the Dy-based MOF shows better adsorption property and selectivity toward Pb(ii) and Cu(ii) ions. Adsorption isotherms indicate that sorption of Pb(ii) and Cu(ii) on MOFs is via monolayer coverage. Preconcentration is based on solid-phase extraction in which MOFs were rapidly injected into water samples and adsorption of metal ions was rapid because of good contact with analyte; then adsorbed Pb(ii) and Cu(ii) ions were analyzed by FAAS. The optimized methodology represents good linearity between 1 and 120 μg L(-1) and detection limit of 0.4 and 0.26 μg L(-1) for Pb(ii) and Cu(ii), respectively. Subsequently the method was evaluated for preconcentration of target metal ions in some environmental water samples.

Goal‐Directed Design of Metal–Organic Frameworks for HgII and PbII Adsorption from Aqueous Solutions

“…Several factors such as electrostatic interactions, covalent interaction, size and shape of the pores, etc. can have an effect on the selectivity of adsorption . One typical example is functionalization of unsaturated Cr 3+ metal centers of ultra‐stable MIL‐101(Cr) by ethanediamine.…”

“…can have an effect on the selectivityo fa dsorption. [42] One typical example is functionalization of unsaturated Cr 3 + metal centers of ultra-stable MIL-101(Cr) by ethanediamine. After grating, the adsorption capacity of MIL-101(Cr) for Pb 2 + showed that the four-fold increase and the selectivity for Pb 2 + compared with otheri ons, such as Zn 2 + ,Co 2 + ,C u 2 + ,a nd Ni 2 + was greatlyi mproved.…”

A Ce(III)‐Based Coordination Polymer as Sorbent for the Removal of Pb2+ and Cd2+ Ions from Water

“…Adsorption capacity of 1 for Pb 2+ and Cd 2+ is calculated after 30 min using the below equation (Eq. : …”

“…[23] Moreover, some studies were carried out on the adsorptive properties of these coordination polymers. [24] In the continuation to our field of research in the synthesis of coordination polymers with adsorptive properties, [25] here we have reported a new coordination polymer, [Ce 2 (m 3 -atp) 2 (m 2atp)(H 2 O) 8 ].4H 2 O (1), and investigated the adsorptive properties of it for the removal of Cd 2 + and Pb 2 + from water.…”

“…In this connection, coordination polymers based on 2‐aminoterephthalic acid with luminescence properties have been reported . Moreover, some studies were carried out on the adsorptive properties of these coordination polymers …”