Towards high-performance Cs and Sr removal via A coral-like dimethylamine-directed manganese thiostannate: Experimental and DFT calculations

Liqi Liu , Deyun Sun , Chi Ma, Shangqing Chen* , Yafei Guo , Tianlong Deng*

Chemical Engineering Science

//doi.org/10.1016/j.ces.2025.121833

Abstract： The efficient removal of 137Cs and 90Sr from complex aqueous solutions remains a critical challenge in environmental remediation. Herein, we present a unique coral-like dimethylamine-directed manganese thiostannate ion exchanger (MTIE) via a facile one-pot solvothermal method. Kinetic studies demonstrated ultrafast ion exchange within 10 min, and the Langmuir isotherm model revealed exceptional adsorption capacities of 248.8 mg/g for Cs+ and 144.2 mg/g for Sr2+. DFT calculations provided atomic-level insights into the adsorption mechanism, revealing lower incorporation energies for Cs+ (− 3.63 eV) and Sr2+ (− 2.79 eV) compared to competing ions, and reduced band gaps that facilitate efficient electron transfer. The adsorption mechanism was identified as a combination of ion exchange and Cs/Sr…S interactions, with characteristic bond distances of 3.03 Å and 3.10 Å. Furthermore, MTIE demonstrated excellent selectivity and recyclability after five regeneration cycles. These findings highlight the potential of MTIE as a practical and efficient solution for radioactive wastewater treatment.