A versatile MOF-based trap for heavy metal ion capture and dispersion

Abstract

Current technologies for removing heavy metal ions are typically metal ion specific. Herein we report the development of a broad-spectrum heavy metal ion trap by incorporation of ethylenediaminetetraacetic acid into a robust metal-organic framework. The capture experiments for a total of 22 heavy metal ions, covering hard, soft, and borderline Lewis metal ions, show that the trap is very effective, with removal efficiencies of >99% for single-component adsorption, multi-component adsorption, or in breakthrough processes. The material can also serve as a host for metal ion loading with arbitrary selections of metal ion amounts/types with a controllable uptake ratio to prepare well-dispersed single or multiple metal catalysts. This is supported by the excellent performance of the prepared Pd2+-loaded composite toward the Suzuki coupling reaction. This work proposes a versatile heavy metal ion trap that may find applications in the fields of separation and catalysis.

Highest and Fastest Removal Rate of PbII Ions through Rational Functionalized Decoration of a Metal–Organic Framework Cavity

“…Unfortunately,t he attempts were not successful and larger single crystals could not be obtained. [22] Moreover,w hen the sorptionp rocess proceeds, two other clear shifts can be recognized in the IR spectrum. [20] To investigate the probablea dsorption mechanism, extended characterization techniques including infrared spectroscopy, PXRD experiments, and X-ray photoelectron spectroscopy (XPS) were conducted.…”

“…As illustrated in Figure 8, after Pb II adsorption,n ew peaks appeared in the XPS spectrum, which can be attributed to Pb 4f, Pb 4d, and Pb 4p. [22] In addition, as illustrated in the high-resolution XPS spectra (Figures S16 and S17 in the Supporting Information), after adsorption of Pb II ions, the peaks of O1sa nd C1s are all shiftedt oh igher binding energies, suggesting the formation of Pb-O or Pb-OC bonding within the framework. [13c, 24] Upon Pb II loading, the core level of N1si ss hifted to am uch higherb inding energy (401.04 eV and4 01.87 eV forl ow and high concentrations of Pb II ions, respectively) in comparison to as-synthesized TMU-56 (400.28 eV), which is indicative of the valance change of the Na tom in the oxamide motif owing to the interaction with the Pb II ions ( Figure S15 in the Supporting Information).…”

Recent Progress in the Removal of Heavy Metal Ions from Water Using Metal‐Organic Frameworks

“…In 2018, Peng et al. proposed the creation of a broad‐spectrum HMIs trap (BS‐HMT) with strong metal chelating groups by grafting ethylene diamine tetraacetic acid (EDTA) to MOF‐808 (Figure ) . The resulting BS‐HMT, MOF‐808‐EDTA, demonstrated good single‐component uptake performance for 22 metal ions, containing soft, hard and borderline acids, and then remove them with >99% efficiency.…”

“… Schematic image of the BS‐HMT significance; (a) The ordered HCOOH in MOF‐808 can be substituted by EDTA to form (b) MOF‐808 with ordered EDTA, which can be used as (c) a BS‐HMT for metal ion catch. Adapted with permission from Ref . Copyright 2018, Elsevier.…”

Cadmium(II)‐Loaded Fe3O4@MPTS Nanoparticles: Preparation and Application as Catalyst for C‐N Coupling Reactions

“…still being used as the homogeneous catalysts for the specific organic transformations . Only a few reports are available for the use of these sorbents in achieving the dual objective of remediation and catalysis applications …”