Large‐scale uranium extraction from seawater is a crucial but challenging part of nuclear power generation. In this study, a new ion‐crosslinked supramolecular Zn2+–poly(amidoxime) (PAO) hydrogel that can super‐efficiently adsorb uranium from seawater is explored. By simply mixing two solutions of zinc chloride and PAO, a supramolecular Zn2+–PAO hydrogel is achieved via the interaction between zinc cations and amidoxime anions. In contrast with existing amidoxime‐functionalized hydrogel‐based adsorbents having low PAO contents and fiber‐based adsorbents with weak hydrophilicity, the PAOs can be directly crosslinked using a small quantity of superhydrophilic zinc ion. Thus, a supramolecular hydrogel is formed, having both a high content of well‐dispersed PAOs and good hydrophilicity. Relative to reported adsorbents, this low‐cost hydrogel membrane exhibits outstanding uranium adsorption performance, reaching 1188 mg g-1 of MU/Mdry gel in 32 ppm uranium‐spiked water. More importantly, after immersion in natural seawater for only 4 weeks, the uranium extraction capacity of the Zn2+–PAO hydrogel membrane reaches 9.23 mg g-1 of MU/Mdry gel. This work can provide a general strategy for designing a new type of supramolecular hydrogel, crosslinked by various bivalent/multivalent cation‐crosslinkers and even many other superhydrophilic supramolecular crosslinkers, for the high‐efficient and massive extraction of uranium from seawater.

Silver chalcogenolate cluster assembled materials (SCAMs) are a category of promising light-emitting materials the luminescence of which can be modulated by variation of their building blocks (cluster nodes and organic linkers). The transformation of a singly emissive [Ag (SBu ) (CF COO) (bpy) ] (Ag bpy, bpy=4,4'-bipyridine) into a dual-emissive [(Ag (SBu ) (CF COO) (bpy) )] (Ag bpy-2) via cluster-node isomerization, the critical importance of which was highlighted in dictating the photoluminescence properties of SCAMs. Moreover, the newly obtained Ag bpy-2 served to construct visual thermochromic Ag bpy-2/NH by a mixed-linker synthesis, together with dichromatic core-shell Ag bpy-2@Ag bpy-NH -2 via solvent-assisted linker exchange. This work provides insight into the significance of metal arrangement on physical properties of nanoclusters.

The uranium level in seawater is ≈1000 times as high as terrestrial ores and can provide potential near‐infinite fuel for the nuclear energy industry. However, it is still a significant challenge to develop high‐efficiency and low‐cost adsorbents for massively extracting uranium from seawater. Herein, a simple and fast method through low‐energy consumption sunlight polymerization to direct fabrication of a poly(amidoxime) (PAO) hydrogel membrane, which exhibits high uranium adsorption capacity, is reported. This PAO hydrogel owns semi‐interpenetrating structure and a hydrophilic poly(acrylamide) 3D network of hydrogel which can disperse and fix PAOs well. As a result, the amidoxime groups of PAOs exhibit an outstanding uranium adsorption efficiency (718 ± 16.6 and 1279 ± 14.5 mg g −1 of m uranium / m PAO in 8 and 32 ppm uranium‐spiked seawater, respectively) among reported hydrogel‐based adsorbents. Most importantly, U‐uptake capacity of this hydrogel can achieve 4.87 ± 0.38 mg g −1 of m uranium / m dry gel just after four weeks within natural seawater. Furthermore, this hydrogel can be massively produced through low‐energy consumption and environmentally‐friendly sunlight polymerization. This work will provide a high‐efficiency and low‐cost adsorbent for massive uranium extraction from seawater.

No abstract

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]− (1⋅CH3OH) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]− cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1⋅CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]− (1), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]− units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]− clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d/l‐valinol(18‐crown‐6)]+[Cu5(StBu)6]− (d/l‐Cu5V), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1⋅CH3OH and mesomeric 1.