Molten salt synthesis of MXene-derived hierarchical titanate for effective strontium removal

Siyi Wang; Pengcheng Zhang; Enzhao Ma; Suwen Chen; Zijie Li; Liyong Yuan; Jianhua Zu; Lin Wang; Weiqun Shi

doi:10.1016/j.jhazmat.2024.134079

Molten salt synthesis of MXene-derived hierarchical titanate for effective strontium removal

J Hazard Mater. 2024 May 5:469:134079. doi: 10.1016/j.jhazmat.2024.134079. Epub 2024 Mar 19.

Authors

Siyi Wang¹, Pengcheng Zhang¹, Enzhao Ma², Suwen Chen³, Zijie Li², Liyong Yuan², Jianhua Zu⁴, Lin Wang⁵, Weiqun Shi⁶

Affiliations

¹ School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000,China; Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
² Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
³ School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000,China.
⁴ School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: zujianhua@sjtu.edu.cn.
⁵ Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. Electronic address: linwang@ihep.ac.cn.
⁶ Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. Electronic address: shiwq@ihep.ac.cn.

PMID: 38521042
DOI: 10.1016/j.jhazmat.2024.134079

Abstract

The removal and recovery of radioactive Sr(II) from wastewater and seawater has been of great concern due to the negative environmental impacts of nuclear energy development and the potential risk of nuclear accidents. Herein, a facile molten salt synthesis strategy was developed to systematically investigated the reaction of different types of MXenes with nitrates. Among the products, K⁺ intercalated hierarchical titanate nanostructures (K-HTNs) obtained from the direct chemical transformation of multilayered Ti₃C₂T_x exhibited unique layered structures, good physicochemical properties, and outstanding adsorption performance for Sr(II). The maximum adsorption capacity of Sr(II) by K-HTNs reached 204 mg·g^-1 at ambient temperature, and the good regeneration and reusability of the titanate was also demonstrated. K-HTNs showed preferential selectivity for Sr(II) in different environmental media containing competing ions, and the removal efficiency of Sr(II) in real seawater was as high as 93.3 %. The removal mechanism was elaborated to be the exchange of Sr²⁺ with K⁺/H⁺ in the interlayers of K-HTNs, and the adsorbed Sr(II) had a strong interaction with Ti-O^- termination on the titanate surface. Benefiting from the merits of rapid and scalable synthesis and excellent adsorption performance, MXene-derived K-HTNs have broad application prospects for the purification of ⁹⁰Sr-contaminated wastewater and seawater.

Keywords: (90)Sr(II) adsorption; MXene; Molten salt method; Potassium titanate nanostructures; Seawater.