Uranium capture from seawater could solve increasing energy demand and enable a much needed relaxing from fossil fuels. Low concentration (∼3 ppb), competing cations (especially vanadium) and pH-dependent speciation prohibit highly efficient uranium uptake. Despite intensive research, selective extraction of uranyl ions over vanadyl units remains a tremendous challenge. Here, we adopted a molecular coordination template strategy to design a uranyl-specific bis-salicylaldoxime entity and decorated it into a highly porous aromatic framework (PAF-1) by programmable assembly. The superstructure (MISS-PAF-1) gives a strong affinity that removes 99.97% of uranium in 120 min. Notably, it binds to the uranyl ion at least 100 times more selectively than 14 different cations tested, including the vanadyl ion, in simulated seawater at ambient pH. Real seawater samples collected from the Bohai Sea achieve 5.79 mg g–1 of uranium capacity over 56 days without PAF degradation, exceeding a 4-fold higher amount than commercial adsorbents.
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机译：从海水中捕获铀可以解决不断增长的能源需求，并使人们迫切需要摆脱化石燃料。低浓度（〜3 ppb），竞争性阳离子（尤其是钒）和pH依赖的物种阻止了铀的高效吸收。尽管进行了深入研究，但在钒基单元上选择性提取铀酰离子仍然是巨大的挑战。在这里，我们采用了分子配位模板策略来设计一个特定于铀酰的双水杨醛肟实体，并通过可编程组装将其装饰成高度多孔的芳族骨架（PAF-1）。上层结构（MISS-PAF-1）具有很强的亲和力，可在120分钟内除去99.97％的铀。值得注意的是，在环境pH值的模拟海水中，它与铀酰离子的选择性比被测试的14种不同阳离子（包括钒离子）的结合选择性高至少100倍。从渤海收集的真实海水样品在56天内达到了5.79 mg g –1 的铀容量，且未发生PAF降解，是商业吸附剂的四倍多。
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