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Marine biofouling is one of the most significant challenges hindering practical uranium extraction from seawater. Single atoms have been widely used in catalytic applications because of their remarkable redox property, implying that the single atom is highly capable of catalyzing the generation of reactive oxygen species (ROS) and acts as an anti‐biofouling substance for controlling biofouling. In this study, the Co single atom loaded polyacrylamidoxime (PAO) material, PAO‐Co, is fabricated based on the binding ability of the amidoxime group to uranyl and cobalt ions. Nitrogen and oxygen atoms from the amidoxime group stabilize the Co single atom. The fabricated PAO‐Co exhibits a broad range of antimicrobial activity against diverse marine microorganisms by producing ROS, with an inhibition rate up to 93.4%. The present study is the first to apply the single atom for controlling biofouling. The adsorbent achieves an ultrahigh uranium adsorption capacity of 9.7 mg g−1 in biofouling‐containing natural seawater, which decreased only by 11% compared with that in biofouling‐removed natural seawater. These findings indicate that applying single atoms would be a promising strategy for designing biofouling‐resistant adsorbents for uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

The extraction of uranium from seawater, which is an abundant resource, has attracted considerable attention as a viable form of energy‐resource acquisition. The two critical factors for boosting the chemical thermodynamics of uranium extraction from seawater are the availability of sufficient amounts of uranyl ions for supply to adsorbents and increased interaction temperatures. However, current approaches only rely on the free diffusion of uranyl ions from seawater to the functional groups within adsorbents, which largely limits the uranium extraction capacity. Herein, inspired by the mechanism of plant transpiration, a plant‐mimetic directional‐channel poly(amidoxime) (DC‐PAO) hydrogel is designed to enhance the uranium extraction efficiency via the active pumping of uranyl ions into the adsorbent. Compared with the original PAO hydrogel without plant‐mimetic transpiration, the uranium extraction capacity of the DC‐PAO hydrogel increases by 79.33% in natural seawater and affords the fastest reported uranium extraction average rate of 0.917 mg g−1 d−1 among the most state‐of‐the‐art amidoxime group‐based adsorbents, along with a high adsorption capacity of 6.42 mg g−1 within 7 d. The results indicate that the proposed method can enhance the efficiency of solar‐transpiration‐based uranium extraction from seawater, particularly in terms of reducing costs and saving processing time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic-single-molecular material is used for uranium adsorption for the first time. • Fully exposure of functional group guarantees high uranium adsorption capacity. • The magnetism of the adsorbent endows it with high recyclability and reusability. • High adsorption capacity of 84.31 mg/g is achieved in simulated nuclear wastewater. • Highest uranium adsorption speed is achieved in simulated nuclear wastewater. Highly efficient treatment of uranium contamination is of great importance for the sustainable development of the environment. The recovery of uranium by adsorbents is a feasible strategy for treating uranium contamination. However, due to insufficient exposure of the contact interfaces, currently available adsorbents usually take extremely long time for uranium adsorption. Herein, a magnetic-single-molecular amidoxime adsorbent M−AO−Fc is fabricated for highly efficient recovery of uranium from nuclear wastewater by endowing the amidoximated cyanoferrocene with magnetism. The adsorbent M−AO−Fc shows a maximum uranium adsorption capacity of 510.60 mg/g in uranium solution. In an acidic simulated nuclear wastewater containing a large number of interfering ions, M−AO−Fc also shows a high uranium adsorption capacity of 84.31 mg/g within a short equilibrium time of 60 min. The full dispersion of M−AO−Fc and full exposure of functional groups are the critical reasons for the excellent uranium adsorption performance. Attributing to the magnetism of M−AO−Fc, this adsorbent can be efficiently recovered by magnetic recovery and shows high reusability. This study proves that the magnetic-single-molecule would be a promising adsorbent for uranium recovery and opens up a new direction for designing a uranium adsorbent. [ABSTRACT FROM AUTHOR]