Enrichment of uranium from seawater is a promising method for addressing the energy crisis. Current technologies are generally not effective for enriching uranium from seawater because its concentration in seawater is low. In this study, new Fe₃O₄@MnO_x with 3D hollow structure, which is capable of enriching low concentration uranium, was prepared via a novel redox etching method. The physicochemical characteristics of Fe₃O₄@MnO_x were studied with TEM, HRTEM, SEAD, FTIR, XRD, and N₂ adsorption-desorption analysis. Dynamic kinetic studies of different initial U(VI) concentrations revealed that the pseudo-second-order model fit the sorption process better, and the sorption rates of Fe₃O₄@MnO_x in 1, 10, and 25 mg/L U(VI) solution were 0.0124, 0.00298, and 0.000867 g/mg·min, respectively. Isothermal studies showed that the maximum sorption amounts were 50.09, 56.27, and 64.62 mg/g for 1, 10, and 25 mg/L U(VI), respectively, at pH 5.0 and 313 K, suggesting that Fe₃O₄@MnO_x could effectively enrich low concentration U(VI) from water. The sorption amount of U(VI) did not significantly decrease in the presence of Na⁺, Mg²⁺, and Ca²⁺. HRTEM, FTIR, and XPS results demonstrated that Fe(II) and Mn/Fe–O–H active sites in Fe₃O₄@MnO_x were accounted for the high and specific enrichment efficiency. A column experiment was conducted to evaluate the U(VI) sorption efficiency of Fe₃O₄@MnO_x in simulated seawater. The U(VI) sorption efficiency remained above 80% in 28 days run. Our findings demonstrate that Fe₃O₄@MnO_x has extraordinary potential for the enrichment of uranium from simulated seawater.

从海水中浓缩铀是解决能源危机的一种很有前景的方法。目前的技术通常不能有效地从海水中浓缩铀，因为它在海水中的浓度很低。在这项研究中，通过一种新型的氧化还原蚀刻方法制备了具有 3D 中空结构的新型 Fe ₃ O ₄ @MnO _x，能够富集低浓度铀。Fe ₃ O ₄ @MnO _x的理化特性通过TEM、HRTEM、SEAD、FTIR、XRD和N _{2 进行了研究}吸附-解吸分析。不同初始 U(VI) 浓度的动态动力学研究表明，伪二级模型更适合吸附过程，Fe ₃ O ₄ @MnO _x在1、10和 25 mg/LU(VI) ) 溶液分别为 0.0124、0.00298 和 0.000867 g/mg·min。等温研究表明，在 pH 5.0 和 313 K 条件下，1、10和 25 mg/LU(VI) 的最大吸附量分别为 50.09、56.27 和 64.62 mg/g，表明 Fe ₃ O ₄ @MnO _x可以有效地从水中富集低浓度的 U(VI)。在Na ⁺、Mg ²⁺存在下U(VI)的吸附量没有显着降低, 和 Ca ²⁺。HRTEM、FTIR 和 XPS 结果表明 Fe(II) 和 Mn/Fe-O-H 活性位点在 Fe ₃ O ₄ @MnO _x中具有高且特定的富集效率。进行柱实验以评估 Fe ₃ O ₄ @MnO _x在模拟海水中的 U(VI) 吸附效率。U(VI) 吸附效率在 28 天的运行中保持在 80% 以上。我们的研究结果表明，Fe ₃ O ₄ @MnO _x具有从模拟海水中富集铀的非凡潜力。