纳米零价铁插层MXenes的结构调控及其对铀酰离子的吸附机制

Using the appropriate adsorbent for radioactive contamination adsorption is one of the most efficient ways to solve the radioactive pollution at present. Among these adsorbents, MXene, that was one of the most widely investigate 2D materials in recent years, could be one of the best candidate for the adsorption of uranyl ions because of their unique nanosheet structure and highly radiation resistance and thermal stability. However, the surface functional groups of MXene are not very rich, the binding sites are limited, and the interlayer spacing is too small to allow the penetration of uranyl ions. All these problems restrict the adsorption performance of MXenes. In this project, the Fe ions are intercalated into the MXene to expand the distance between each layer of MXene, and then Fe ions were reduced into Nano Zero Valent Irons (nZVI). The adsorption performance of as-prepared nZVI/MXenes could be improved by the synergistic effect between nZVI and MXenes. The mechanism of the interaction of nZVI/MXene composites with uranyl ions, and the relationship between the special structure and adsorption properties of the composite will be discussed in this project. It is hope that we could develop a highly efficient adsorbent for uranyl or other radioactive materials by means of understanding the performance of MXenes, at the same time, enrich the database of radioactive material adsorption materials that is of great importance in research area of adsorption.

选择性能优越的吸附材料对放射性污染物进行吸附处理是目前解决放射性污染及其废物治理的有效手段之一。二维金属碳化物（MXenes）具有大密度，独特的层状结构,优异的耐辐照性能和热稳定性，在铀酰离子等放射物质的吸附方面具有重要应用。然而表面官能团不丰富，层间距太小是制约其发展的主要因素。本项目利用羟基对MXenes进行表面改性，增加其表面的官能团；利用Fe离子对羟基改性后的MXenes进行插层处理，通过Fe离子的进入和原位还原形成纳米零价铁（nZVI）增大其层间距。MXenes表面的羟基、插层的nZVI和MXenes三者协同作用对复合材料吸附性能的影响是本项目研究的重点，而nZVI/MXenes复合材料与铀酰离子相互作用的机制及其插层结构与吸附性能的构效关系是本研究拟解决的关键科学问题。本项目研究旨在为基于MXenes的新型高效、耐辐照吸附材料的结构设计及应用提供重要科学依据。

选择性能优越的吸附材料对放射性污染物进行吸附处理是目前解决放射性污染及其废物治理的有效手段之一。二维金属碳化物(MXenes)具有大密度，独特的层状结构,优异的耐辐照 性能和热稳定性，在铀酰离子及其模拟物吸附方面具有重要应用。然而表面官能团不丰富，层间距太小是制约其发展的主要因素。本项目利用羟基对MXenes进行表面改性，增加其表面的官能团;利用Fe离子对羟基改性后的MXenes进行插层处理，通过Fe离子的进入和原位还原形成 纳米零价铁(nZVI)增大其层间距。实验结果表明MXenes表面的羟基、插层的nZVI和MXenes三者协同作用可以有效提高MXene的吸附性能。同时，Ca2+离子改性的MXenes复合凝胶可以同时吸附有机磷污染物和铀酰离子。项目还得到了铀酰离子与MXenes复合材料相互作用的机制。本项目的结论对开发基于MXenes的新型高效、耐辐照吸附材料的结构设计及应用提供了重要科学依据。