Tailor-Made Multiple Interpenetrated Metal–Organic Framework for Selective Detection and Adsorption of ReO₄^–

Abstract

Rationally designed new materials for the selective detection and adsorption of 99Tc, a problematic element in nuclear waste, are important and challenging in environmental monitoring. Here, we utilize an interpenetration approach to develop a cationic fluorescent metal–organic framework (NCU-2), which was constructed by a flexible tridentate nitrogen-containing ligand and Ag+ metal ions. The NCU-2 is a scarce case of 14-fold interpenetrated with excellent chemical stability even under 0.5 M HNO3, which is helpful for the detection and removal of ReO4 –/TcO4 – from nuclear waste. Excitingly, the fluorescence signal of NCU-2 was obviously quenched in the presence of ReO4 – (a nonradioactive surrogate of TcO4 –) due to the robust interaction between ReO4 – and the host for the formation of a non-fluorescent complex. Furthermore, the NCU-2 exhibits a high selectivity sensing of ReO4 – in the presence of excess competitive ions. The superior response of NCU-2 toward ReO4 – is ascribed to the high-fold structure and the luxuriant unsaturated Ag metal sites on the wall of 1D pore channels, which can enhance the framework positive charge and accelerate the transport of guest molecules to strengthen the interaction between them. Notably, NCU-2 successfully quantified trace levels of ReO4 – in simulated Hanford waste with a broad linear range (0.2–200 μM) and a low detection limit of 66.7 nM. Moreover, NCU-2 also shows a high adsorption capacity to ReO4 – (541 mg/g) and rapid sorption kinetics, making it extremely attractive for waste monitoring and emergency remediation.

Lanthanide Metal–Organic Framework Isomers with Novel Water-Boosting Lanthanide Luminescence Behaviors

“…As shown in Figures S21a–S21c, the O 1s spectra of QXBA-Eu-1 were fitted with two peaks at 531.69 and 533.52 eV, assigned to O–CO and O–H groups, respectively, and the percentage content of the O–H band increased from 6.54% to 10.71%, indicating the increased H 2 O content in framework. In the meantime, N 1s spectra possessed two deconvoluted peaks at 399.34 eV (OC–N from DMA) and 400.94 eV (CN) . Obviously, the percentage content of the OC–N band reduced from 9.91% to 9.09%.…”

“…In the meantime, N 1s spectra possessed two deconvoluted peaks at 399.34 eV (O� C−N from DMA) and 400.94 eV (C�N). 38 Obviously, the percentage content of the O�C−N band reduced from 9.91% to 9.09%. Certainly, the binding energy in Eu 3d spectra kept identical.…”

Advanced Porous Materials as Designer Platforms for Sequestering Radionuclide Pertechnetate

“…Furthermore, NCU-2 displays a high ReO 4 – uptake capacity, measured at 541 mg g –1 , along with rapid sorption kinetics. These characteristics make NCU-2 a highly promising material for applications in waste monitoring and emergency remediation, especially for trace-level detection and quantification of ReO 4 – in challenging environments …”

“…− in challenging environments. 76 ■ COF-BASED SORBENTS COFs are materials composed of 2D or 3D networks formed through reactions between organic precursors. These reactions result in strong covalent bonds, yielding porous, stable, and crystalline structures.…”

Ionic covalent organic framework for selective detection and adsorption of TcO4−/ReO4−

“…. 5 Re is one of the most precious and rare elements on Earth. 6 Thanks to its prominent malleability and high melting point, it has been widely used in the catalysis of aerospace and unleaded gasoline.…”