Selective Adsorption of Rare Earth Elements by Zn-BDC MOF/Graphene Oxide Nanocomposites Synthesized via In Situ Interlayer-Confined Strategy

Abstract

Separation of rare earth elements has always been an urgent problem in the industry. Although a variety of adsorption materials have been developed for the adsorption and separation of rare earth elements, it is difficult to achieve high adsorption capacity and high separation selectivity from most of them at the same time. In this work, to combine the advantages of the good adsorption capacity of graphene oxide (GO) and high separation selectivity of metal organic frameworks (MOFs), two-dimensional MOFs and GO nanocomposite materials (2D Zn-BDC MOF/GO) were synthesized by a solvothermal interlayer-confined strategy. The composite material has a maximum adsorption capacity of 344.48 mg/g for rare earth ions, with the selectivity of Sc/Tm ≈ 529.57, Sc/Er ≈ 461.91, Sc/Y ≈ 445.70, and Tm/Eu ≈ 4.55. This work brings us a new route to synthesize 2D MOF/GO nanocomposite materials and combine their advantages for the separation of rare earth elements in chemical engineering research.

Enhanced adsorption and synergistic photocatalytic degradation of tetracycline by MOF-801/GO composites via solvothermal synthesis

“…17 It has the advantages of high porosity, large specific surface area, low density, adjustable pore size, regular pore structure and topological diversity, tailoring and semiconductor properties, showing great application potential in adsorption, separation, sensing, catalysis and energy. [18][19][20][21][22][23][24][25] Theoretically, MOFs can serve as potential candidates for photocatalysts because of their richness in metal clusters and bridging organic linkers, which can efficiently absorb light and transfer photogenerated electrons to metal-oxygen clusters. Among various MOFs, MOF-801(Zr) is often used in adsorption, hydrogen storage and sensing due to its excellent stability and small pore size.…”

Nanoporous Sulfonic Covalent Organic Frameworks for Selective Adsorption and Separation of Lanthanide Elements

“…The majority of SFs were superior to those in previous reports (Table ). ,,− All of the results indicate that the TFPB-DABDA iCOFs exhibit promising separation performance for the lanthanides.…”

“…As displayed in Figure a, the removal of La­(III) by TFPB-DABDA iCOFs gradually increases with the increased pH value, and the maximal removal rate is observed at pH 4.0. As can be seen in Figure b, the ζ potential results of TFPB-DABDA iCOFs decrease with the increase of pH, which can be attributed to the fact that the surface sulfonic groups are gradually deprotonated and the material has the better stability of colloidal dispersion at pH 4.0 . Enhancement of the electrostatic attraction between the material and the lanthanide ions by the negative charge on the surface of TFPB-DABDA iCOFs leads to an increased adsorption capacity.…”

“…Nevertheless, there are limitations such as time-consuming, low efficiency, high temperature, and poor separation between adjacent lanthanides. Recently, solid adsorption materials have become the most cost-effective, simple to operate, and environmentally friendly separation technology. , Emerging materials such as silica-based materials, carbon-based adsorbents, metal–organic frameworks and their composites are used in the selective adsorption separation of rare earth elements (REEs) and have shown good performance. − It is reported that the subtle differences in the ionic radius play an important role in separation efficiency. , Therefore, it is important to develop new adsorption materials with higher separation performance through rational design and synthesis to amplify the difference in ionic radius …”

Adsorption-based Separation and Recovery of Rare Earth Elements

“…461.91, and Sc/Y [?] 445.70 (Chen et al, 2022). It was also selective for Tm and Er with SFs for Tm/Eu [?]…”