TY - JOUR
T1 - Selective Capture Mechanism of Radioactive Thorium from Highly Acidic Solution by a Layered Metal Sulfide
AU - Xu, Lei
AU - Xu, Chao
AU - Bao, Hongliang
AU - Spanopoulos, Ioannis
AU - Ke, Weijun
AU - Dong, Xue
AU - Xiao, Chengliang
AU - Kanatzidis, Mercouri G.
N1 - Funding Information:
This work at Northwestern University was supported in part by the National Science Foundation through grant DMR-2003476. C.X. also thank the National Natural Science Foundation of China (Nos. 21876124, U1732112, and 21822606) and the Fundamental Research Funds for the Central Universities (2020QNA4035).
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/11
Y1 - 2021/8/11
N2 - Thorium as a potential nuclear fuel for the next-generation thorium-based molten salt reactors holds significant environmental and economic promise over the current uranium-based nuclear reactors. However, because thorium (Th4+) usually coexists with other rare earth elements, alkali or alkaline earth metals in minerals, or highly acidic radioactive waste, seeking acid-resistant sorbents with excellent selectivity, high capacity, and fast removal rate for Th4+ is still a challenging task. In this work, we investigated a robust layered metal sulfide (KInSn2S6, KMS-5) for Th4+ removal from strong acidic solutions. We report that KMS-5 could capture Th4+ from a 0.1 M HNO3 solution with extremely high efficiency (∼99.9%), fast sorption kinetics (equilibrium time < 10 min), and large distribution coefficient (up to 1.5 × 106 mL/g). Furthermore, KMS-5 exhibited excellent sorption selectivity towards Th4+ in the presence of large amounts of competitive metal ions like Eu3+, Na+, and Ca2+. This extraordinary capture property for Th4+ is attributed to the facile ion exchange of Th4+ with K+ in the interlayers and subsequent formation of a stable coordination complex via Th-S bonds. These results indicate that KMS-5 is a promising functional sorbent for the effective capture of Th4+ from highly acidic solutions.
AB - Thorium as a potential nuclear fuel for the next-generation thorium-based molten salt reactors holds significant environmental and economic promise over the current uranium-based nuclear reactors. However, because thorium (Th4+) usually coexists with other rare earth elements, alkali or alkaline earth metals in minerals, or highly acidic radioactive waste, seeking acid-resistant sorbents with excellent selectivity, high capacity, and fast removal rate for Th4+ is still a challenging task. In this work, we investigated a robust layered metal sulfide (KInSn2S6, KMS-5) for Th4+ removal from strong acidic solutions. We report that KMS-5 could capture Th4+ from a 0.1 M HNO3 solution with extremely high efficiency (∼99.9%), fast sorption kinetics (equilibrium time < 10 min), and large distribution coefficient (up to 1.5 × 106 mL/g). Furthermore, KMS-5 exhibited excellent sorption selectivity towards Th4+ in the presence of large amounts of competitive metal ions like Eu3+, Na+, and Ca2+. This extraordinary capture property for Th4+ is attributed to the facile ion exchange of Th4+ with K+ in the interlayers and subsequent formation of a stable coordination complex via Th-S bonds. These results indicate that KMS-5 is a promising functional sorbent for the effective capture of Th4+ from highly acidic solutions.
KW - EXAFS
KW - acid-resistant sorbent
KW - ion exchange
KW - layered metal sulfide
KW - thorium capture
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U2 - 10.1021/acsami.1c12004
DO - 10.1021/acsami.1c12004
M3 - Article
C2 - 34324297
AN - SCOPUS:85112550157
SN - 1944-8244
VL - 13
SP - 37308
EP - 37315
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 31
ER -