The highly luminous lanthanide metal−organic gels (Ln-MOGs) can act as fluorescent probes for the detection of organic amines and can also be used to build white-light emitting materials according to...

Uranium is one of the principal raw materials in the nuclear industry, but if released into the natural environment, it also poses latent health risks to mankind. Therefore, there is an urgent need to develop a strategy that can concurrently detect and adsorb uranium to realize the sustainable development of nuclear power and protect the environment. In this work, a fluorescent zinc-based metal–organic framework (HNU-50) was designed and synthesized for the effective detection and extraction of U­(VI). The amide groups on N-pyridin-4-ylpyridine-4-carboxamide ligands and two uncoordinated carboxyl oxygen atoms on pyromellitic acid ligands in HNU-50 provide potential uranium-binding sites. Consequently, HNU-50 is competent of selectively and efficiently catching uranyl ions, achieving an optimum adsorption capacity of 632 mg/g. Additionally, the adsorption of U­(VI) results in fluorescence quenching of HNU-50, thus allowing sensitive and selective detection of U­(VI) by fluorescence change. Note that HNU-50 exhibits a considerably low detection limit of 1.2 × 10–8 M for U­(VI) in aqueous solution, which is below the World Health Organization maximum pollution standards for potable water (6.3 × 10–8 M).

A uranium-based metal–organic framework, [(UO2)­(H2DTATC)] (HNU-39, H4DTATC = 5,5′-(9,10-dihydroxy-4a,9,9a,10-tetrahydroanthracene-9,10-diyl)­diisophthalic acid) was successfully prepared by a hydrothermal method. The structure of HNU-39 comprises UO8 hexagonal bipyramids linked by doubly protonated DTATC ligands, forming a ribbon arrangement. It is worth noting that the DTATC ligand was transformed in situ from 5,5′-(anthracene-9,10-diyl)­diisophthalic acid (H4DPATC) during the synthesis of HNU-39. Research on fluorescence properties has shown that HNU-39 exhibits fluorescence turn-on response under alkaline conditions and could be used as a potential pH sensor. Moreover, HNU-39 can also be successfully applied for pH sensing in real samples from a sewage treatment plant. The sensing mechanism can be interpreted as OH– ions reacting with the protons in the organic ligand of HNU-39.

Stable presence of U(V)-containing compounds is important for the study of radionuclides. However, pentavalent uranium is prone to disproportionation, thus U(V)-containing compounds are generally sensitive to air and water. Herein,...