Zhang Shuang, Yang Fan, Cao Xiaohui, Tang Yong, Yin Taiqi, Bo Tao, Liu Yunhai, Lisak Grzegorz, Kano Naoki, Na Bing, Chang Mengyu, Liu Yuhui
Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices, East China University of Technology, Nanchang 330013 Jiangxi, China; State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013 Jiangxi, China.
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013 Jiangxi, China.
J Hazard Mater. 2023 Oct 5;459:132112. doi: 10.1016/j.jhazmat.2023.132112. Epub 2023 Jul 22.
Numerous efforts have been devoted to understanding the electron transfer process of uranium (UO) on adsorbent materials, whereas the potential oxygen vacancies (OVs) in metal oxides have long been overlooked. Once these interactions are taken into account, the emerging molecular orbital effects undoubtedly affect the adsorption process. Here, we synthesized CC/γ-MnO by growing MnO on carbon cloth (CC), followed by the creation of oxygen vacancies (OVs) through electrochemical methods to form CC/γ-MnO-OVs. The CC/γ-MnO-OVs shows significantly enhanced selectivity and durability for UO, with the maximum adsorption capacity increasing from 456.8 to 1648.1 mg/g (by a factor of 3.6). Theoretical calculations suggest that the generation of OVs leads to an increase in charge transfer and a decrease in adsorption energy between UO and CC/γ-MnO, due to the interaction between Mn 3d orbital in CC/γ-MnO and O 2p orbital in UO. The OVs in CC/γ-MnO provide a spatial structure for anchoring the OU=O moiety of UO, while the surface van der Waals forces and the formation of chemical bonds between Mn-U contribute to charge interactions. This synergistic effect allows CC/γ-MnO-OVs to exhibit favorable selectivity, a large adsorption capacity, and rapid adsorption kinetics towards uranyl ions. This work achieves enhanced UO separation by introducing OVs in CC/γ-MnO through a facile electrochemical strategy, highlighting the great potential for nuclear waste processing.
人们已经做出了许多努力来理解铀（UO）在吸附剂材料上的电子转移过程，而金属氧化物中潜在的氧空位（OVs）长期以来一直被忽视。一旦考虑到这些相互作用，新出现的分子轨道效应无疑会影响吸附过程。在这里，我们通过在碳布（CC）上生长MnO2合成了CC/γ-MnO2，然后通过电化学方法产生氧空位（OVs）以形成CC/γ-MnO2-OVs。CC/γ-MnO2-OVs对UO2+显示出显著增强的选择性和耐久性，最大吸附容量从456.8增加到1648.1mg/g（增加了3.6倍）。理论计算表明，由于CC/γ-MnO2中Mn 3d轨道与UO2+中O 2p轨道之间的相互作用，OVs的产生导致电荷转移增加以及UO2+与CC/γ-MnO2之间的吸附能降低。CC/γ-MnO2中的OVs为锚定UO2+的OU=O部分提供了空间结构，而表面范德华力以及Mn-U之间化学键的形成有助于电荷相互作用。这种协同效应使CC/γ-MnO2-OVs对铀酰离子表现出良好的选择性、大吸附容量和快速吸附动力学。这项工作通过一种简便的电化学策略在CC/γ-MnO2中引入OVs实现了增强的UO2+分离，突出了其在核废料处理方面的巨大潜力。
