Readily regenerated porous fiber-supported metal tin sulfide for rapid and selective removal of cesium from wastewater

The removal of Cs from radioactive wastewater remains a great challenge due to the presence of a large number of coexisting ions. Herein, a novel porous fiber-supported metal tin sulfide named PVC-[Me 2 NH 2 ] 2 Sn 3 S 7 was designed. Specifically, four tin sulfides were prepared by the one-pot method in different solvents. Water was the most suitable solvent since it was essential for converting amides to cations. When three amides were used as precursors, [Me 2 NH 2 ] 2 Sn 3 S 7 prepared with DMF showed the best adsorption performance. Five polymers were then comprehensively evaluated around physicochemical stability, hydrophilicity , and cost to facilitate the engineering application of adsorbents. Finally, polyvinyl chloride (PVC) was selected as the support material. The optimized porous PVC-[Me 2 NH 2 ] 2 Sn 3 S 7 fiber with 50 wt% [Me 2 NH 2 ] 2 Sn 3 S 7 percentage can reach adsorption equilibrium within 30 min, has a wide active pH range of 2–12, and has a high adsorption capacity of 419.01 mg g −1 . When applied to simulated wastewater, the separation coefficients of Cs + and coexisting ions were above 1 × 10 4 . The Cs  +  adsorption enthalpy change was obtained by calorimetric study and simulation calculation. Even after 50 consecutive cycles, the removal efficiency barely decayed. The Cs + concentration could be enriched to 259.93 times that of the geothermal water . The above advantages make PVC-[Me 2 NH 2 ] 2 Sn 3 S 7 a promising adsorbent for selective Cs  +  removal from wastewater.