Extraction of uranium from seawater is of great interest because of its potential applications in the nuclear energy field. In this study, we prepared 3D Fe-inserted and N-doped carbon nanosheet frameworks by a polymer-blowing process, followed by decoration with nickel–manganese layered double hydroxide (Fe-NCNF-LDH). Employing SEM, FTIR, XPS, XRD, TEM, and BET techniques, we confirmed the existence of 3D structured porous materials with advantageous interconnectivity to provide a highly accessible freeway for uranium(VI) ionic diffusion. We investigated the removal of uranium(VI) from an aqueous solution (ppm level) and simulated seawater (ppb level) by the Fe-NCNF-LDH composites. The results showed that the adsorption process fitted well with a pseudo-second-order model and Langmuir isotherm model. Based on XRD and XPS, before and after the adsorption of uranium(VI), we proposed a possible sorption mechanism (anion exchange, chemical reduction, and surface complexation). In addition, the Fe-NCNF-LDH composites show good adsorption properties after five adsorption–desorption cycles, which augur well for potential application in the field of the adsorption of uranium from seawater.

中文翻译：

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Ni-Mn LDH装饰的3D掺铁和N掺杂的碳骨架复合材料，可有效去除铀（vi）†

从海水中提取铀非常重要，因为它在核能领域具有潜在的应用前景。在这项研究中，我们通过聚合物吹塑工艺制备了3D掺铁和掺N的碳纳米片框架，然后用镍锰层状双氢氧化物（Fe-NCNF-LDH）装饰。通过使用SEM，FTIR，XPS，XRD，TEM和BET技术，我们确认了3D结构多孔材料的存在，该材料具有良好的互连性，从而为铀（VI）离子扩散提供了高度可利用的高速公路。我们调查了铀的去除（VIFe-NCNF-LDH复合材料从水溶液（ppm级）和模拟海水（ppb级）中提取）。结果表明，该吸附过程与拟二阶模型和Langmuir等温线模型拟合得很好。基于XRD和XPS，我们提出了铀（VI）吸附前后的可能吸附机理（阴离子交换，化学还原和表面络合）。另外，Fe-NCNF-LDH复合材料在五个吸附-解吸循环后显示出良好的吸附性能，这预示着其在从海水中吸附铀方面的潜在应用。