Layered metal sulfides with MaSbc- framework (M = Sb, In, Sn) as ion exchangers for the removal of Cs(Ⅰ) and Sr(Ⅱ) from radioactive effluents: a review

Qi Zhao; Shuai Wang; Yichun Wu; Yixuan Wang; Shengshou Ma; Kaimin Shih

doi:10.3389/fchem.2023.1292979

Layered metal sulfides with M_aS_b^c- framework (M = Sb, In, Sn) as ion exchangers for the removal of Cs(Ⅰ) and Sr(Ⅱ) from radioactive effluents: a review

Front Chem. 2023 Dec 6:11:1292979. doi: 10.3389/fchem.2023.1292979. eCollection 2023.

Authors

Qi Zhao¹, Shuai Wang², Yichun Wu¹, Yixuan Wang¹, Shengshou Ma¹, Kaimin Shih¹

Affiliations

¹ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR,China.
² School of Metallurgy, Northeastern University, Shenyang, Liaoning, China.

Abstract

Nuclear power has emerged as a pivotal contributor to the global electricity supply owing to its high efficiency and low-carbon characteristics. However, the rapid expansion of the nuclear industry has resulted in the production of a significant amount of hazardous effluents that contain various radionuclides, such as ¹³⁷Cs and ⁹⁰Sr. Effectively removing ¹³⁷Cs and ⁹⁰Sr from radioactive effluents prior to discharge is a critical challenge. Layered metal sulfides exhibit significant potential as ion exchangers for the efficient uptake of Cs⁺ and Sr²⁺ from aqueous solutions owing to their open and exchangeable frameworks and the distinctive properties of their soft S^2- ligands. This review provides a detailed account of layered metal sulfides with M_aS_b ^c- frameworks (M = Sb, In, Sn), including their synthesis methods, structural characteristics, and Cs⁺ and Sr²⁺ removal efficiencies. Furthermore, we highlight the advantages of layered metal sulfides, such as their relatively high ion exchange capacities, broad active pH ranges, and structural stability against acid and radiation, through a comparative evaluation with other conventional ion exchangers. Finally, we discuss the challenges regarding the practical application of layered metal sulfides in radionuclide scavenging.

Keywords: cesium; ion exchange; layered metal sulfides; radioactive effluents; strontium.

Publication types

Review

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The authors acknowledge the research fund provided by the Research Grants Council of Hong Kong (Project No.: 17208120). Publication made possible in part by support from the HKU Libraries Open Access Author Fund sponsored by the HKU Libraries.