Voltage-gated ions sieving through 2d mxene ti₃c₂t_xmembranes

We report a nanochanneled Ti₃C₂T_x MXene membrane that enables an efficient controlled rejection/permeation of inorganic ions and organic dye molecules under applied electrical potential. When a negative electrical potential (-0.6 V) is applied to the Ti₃C₂T_x MXene membrane under only osmotic pressure, the rejection of inorganic salt (NaCl or MgSO₄) through the membrane is enhanced. In contrast, applying a positive potential inhibits the rejection through electrostatic repulsion between charged MXene layers and inorganic cations in solution. The rejection rates of Ti₃C₂T_x membranes are also tested in a flow-through system. MXene membranes as thin as 100 nm show a high rejection rate above 97.9 ± 1.0% for methylene blue dye molecules. Similar to inorganic salts, application of negative or positive voltages increases and decreases, respectively, the transport of molecules through Ti₃C₂T_x membranes. The voltage gated rejection through electronically conductive membranes is demonstrated as a promising alternative to improve rejection of inorganic salts and organic molecules.