Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, and ‡Beijing Key Lab of Radioactive Waste Treatment, Tsinghua University , Beijing 100084, China.
Environ Sci Technol. 2017 Apr 18;51(8):4606-4614. doi: 10.1021/acs.est.7b00470. Epub 2017 Mar 29.
Developing facile and robust technologies for effective enrichment of uranium from seawater is of great significance for resource sustainability and environmental safety. By exploiting mussel-inspired polydopamine (PDA) chemistry, diverse types of PDA-functionalized sorbents including magnetic nanoparticle (MNP), ordered mesoporous carbon (OMC), and glass fiber carpet (GFC) were synthesized. The PDA functional layers with abundant catechol and amine/imine groups provided an excellent platform for binding to uranium. Due to the distinctive structure of PDA, the sorbents exhibited multistage kinetics which was simultaneously controlled by chemisorption and intralayer diffusion. Applying the diverse PDA-modified sorbents for enrichment of low concentration (parts per billion) uranium in laboratory-prepared solutions and unpurified seawater was fully evaluated under different scenarios: that is, by batch adsorption for MNP and OMC and by selective filtration for GFC. Moreover, high-resolution X-ray photoelectron spectroscopic and extended X-ray absorption fine structure studies were performed for probing the underlying coordination mechanism between PDA and U(VI). The catechol hydroxyls of PDA were identified as the main bidentate ligands to coordinate U(VI) at the equatorial plane. This study assessed the potential of versatile PDA chemistry for development of efficient uranium sorbents and provided new insights into the interaction mechanism between PDA and uranium.
开发简便、高效的从海水中富集铀的技术对于资源的可持续性和环境安全具有重要意义。本研究利用贻贝启发的聚多巴胺（PDA）化学，合成了多种 PDA 功能化吸附剂，包括磁性纳米颗粒（MNP）、有序介孔碳（OMC）和玻璃纤维地毯（GFC）。具有丰富儿茶酚和胺/亚胺基团的 PDA 功能层为与铀结合提供了极好的平台。由于 PDA 的独特结构，吸附剂表现出多阶段动力学，同时受化学吸附和层内扩散控制。在不同的情况下，全面评估了使用各种 PDA 修饰的吸附剂从实验室制备的溶液和未净化海水中富集低浓度（十亿分之几）铀的情况：即通过 MNP 和 OMC 的批量吸附以及 GFC 的选择性过滤。此外，还进行了高分辨率 X 射线光电子能谱和扩展 X 射线吸收精细结构研究，以探究 PDA 和 U(VI)之间的配位机制。PDA 的儿茶酚羟基被确定为与 U(VI)在赤道平面配位的主要双齿配体。本研究评估了多功能 PDA 化学在开发高效铀吸附剂方面的潜力，并为 PDA 和铀之间的相互作用机制提供了新的见解。
