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Uranium extraction from seawater has attracted worldwide attention due to the massive reserves of uranium. Due to the straightforward synthesis and strong affinity toward uranyl ions (UO22+), the amidoxime group shows promise for use in highly efficient uranium capture. However, the low mass transfer efficiency within traditional amidoxime‐based adsorbents severely limits the adsorption rate and the utilization of adsorption sites. In this work, a macroporous polyamidoxime (PAO) hydrogel is prepared by yeast‐based biological foaming combined with ice crystal dispersion that effectively maintained the yeast activity. The yeast‐raised PAO (Y‐PAO) adsorbent has numerous bubble‐like holes with an average pore diameter >100 µm. These macropores connected with the intrinsic micropores of PAO to construct efficient diffusion channels for UO22+ provided fast mass transporting channels, leading to the sufficient exposure of hidden binding sites. The maximum adsorption capacity of Y‐PAO membrane reached 10.07 mg‐U/g‐ads, ≈1.54 times higher than that of the control sample. It took only eight days for Y‐PAO to reach the saturation adsorption capacity of the control PAO (6.47 mg‐U/g‐ads, 28 days). Meanwhile, Y‐PAO possessed excellent ion selectivity, good reusability, and low cost. Overall, the Y‐PAO membrane is a highly promising adsorbent for use in industrial‐scale uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

Marine sponges are used as biomonitors of heavy metals contamination in coastal environment as they process large amounts of water and have a high capacity for accumulating heavy metals. Here, inspired by the unique physical and physiological features of marine sponges, a surface engineered synthetic sponge for the highly efficient harvesting of uranium from natural seawater is developed. An ultrathin poly(imide dioxime) (PIDO)/alginate (Alg) interpenetrating polymer network hydrogel layer is uniformly wrapped around the skeleton of a melamine sponge (MS) substrate through a simple dipping–drying–crosslinking process, providing the hybrid MS@PIDO/Alg sponge with excellent uranium adsorption performance and sufficient mechanical strength to withstand the harsh conditions of practical applications. The maximum adsorption capacity reaches 910.98 mg‐U g‐gel‐1 for the PIDO/Alg hydrogel layer and 291.51 mg‐U g‐sponge‐1 for the whole hybrid MS@PIDO/Alg sponge in uranium‐spiked natural seawater. The adsorption capacity measured after 56 d of exposure in 5 tons of natural seawater is evaluated to be 5.84 mg‐U g‐gel‐1 (1.87 mg‐U g‐sponge‐1). This novel approach shows great promise for the mass production of high‐performance sponge adsorbent for uranium recovery from natural seawater and nuclear waste. [ABSTRACT FROM AUTHOR]

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 muranium/mPAO 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 muranium/mdry 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. [ABSTRACT FROM AUTHOR]