Three-Dimensional Ti₃C₂T_x (MXene) Film for Radionuclide Removal From an Aqueous Solution

Two-dimensional MXenes (Ti₃C₂T_x) have received extensive attention due to their easy availability, hydrophilic behavior, and tunable chemical properties; however, their permeability-selectivity trade-off and self-stacking property limits their application in water treatment. In this study, three-dimensional Ti₃C₂T_x films with high adsorption capacity, permeability, and high selectivity were successfully fabricated using a simple vacuum-assisted filtration method for the removal of radionuclides (Cs⁺, Sr²⁺, and Co²⁺) from aqueous solutions. Various characterization results suggested that radionuclides tended to coordinate with heterogeneity of the sites (containing hydroxyl, fluorine, and oxygen groups) on Ti₃C₂T_x, as well as the multilayer adsorption properties of the Ti₃C₂T_x films. The synthesized Ti₃C₂T_x film demonstrated maximum removal efficiencies of 99.50%, 99.54%, and 99.8% for Cs⁺, Sr²⁺ and Co²⁺, respectively, at pH 7 and 25℃. The adsorption behavior and process analysis showed that the adsorption mechanism primarily involves electrostatic and chemical interactions on the Ti₃C₂T_x film. Furthermore, the films not only sequestrated radionuclides from the aqueous solution, but also selectively separated target radionuclides by adjusting the Ti₃C₂T_x interlayer size. Therefore, the newly developed Ti₃C₂T_x films demonstrated great potential for the removal of radionuclides from aqueous solutions.