Liu Xiaolu, Xie Yinghui, Li Yang, Hao Mengjie, Chen Zhongshan, Yang Hui, Waterhouse Geoffrey I N, Ma Shengqian, Wang Xiangke
College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, P. R. China.
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical Sciences, The University of Auckland, Auckland, 1142, New Zealand.
Adv Sci (Weinh). 2023 Oct;10(30):e2303536. doi: 10.1002/advs.202303536. Epub 2023 Sep 10.
The selective removal of the β-emitting pertechnetate ion ( TcO ) from nuclear waste streams is technically challenging. Herein, a practical approach is proposed for the selective removal of TcO (or its surrogate ReO ) under extreme conditions of high acidity, alkalinity, ionic strength, and radiation field. Hollow porous N-doped carbon capsules loaded with ruthenium clusters (Ru@HNCC) are first prepared, then modified with a cationic polymeric network (R) containing imidazolium-N units (Ru@HNCC-R) for selective TcO and ReO binding. The Ru@HNCC-R capsules offer high binding affinities for TcO /ReO under wide-ranging conditions. An electrochemical redox process then transforms adsorbed ReO to bulk ReO , delivering record-high removal capacities, fast kinetics, and excellent long-term durability for removing ReO (as a proxy for TcO ) in a 3 m HNO , simulated nuclear waste-Hanford melter recycle stream and an alkaline high-level waste stream (HLW) at the U.S. Savannah River Site (SRS). In situ Raman and X-ray absorption spectroscopy (XAS) analyses showed that adsorbed Re(VII) is electrocatalytically reduced on Ru sites to a Re(IV)O intermediate, which can then be re-oxidized to insoluble Re(VI)O for facile collection. This approach overcomes many of the challenges associated with the selective separation and removal of TcO /ReO under extreme conditions, offering new vistas for nuclear waste management and environmental remediation.
从核废物流中选择性去除发射β射线的高锝酸根离子（TcO ）在技术上具有挑战性。在此，提出了一种实用方法，用于在高酸度、高碱度、高离子强度和辐射场等极端条件下选择性去除TcO （或其替代物ReO ）。首先制备负载钌簇的中空多孔氮掺杂碳胶囊（Ru@HNCC），然后用含有咪唑鎓-N单元的阳离子聚合物网络（R）进行改性，得到用于选择性结合TcO 和ReO 的Ru@HNCC-R。Ru@HNCC-R胶囊在广泛的条件下对TcO /ReO 具有高结合亲和力。随后，一个电化学氧化还原过程将吸附的ReO 转化为块状ReO ，在3 m HNO 、模拟核废料 - 汉福德熔炉循环流以及美国萨凡纳河 Site（SRS）的碱性高放废液流中，对于去除ReO （作为TcO 的替代物）具有创纪录的高去除容量、快速动力学和出色的长期耐久性。原位拉曼光谱和X射线吸收光谱（XAS）分析表明，吸附的Re(VII)在Ru位点上被电催化还原为Re(IV)O中间体，然后该中间体可再氧化为不溶性的Re(VI)O以便于收集。这种方法克服了在极端条件下选择性分离和去除TcO /ReO 所面临的许多挑战，为核废料管理和环境修复提供了新的前景。
