Application of a Ti₃C₂T_X MXene-Coated Membrane for Removal of Selected Natural Organic Matter and Pharmaceuticals

Ti₃C₂T_X MXene was used for surface modification of membranes by vacuum-assisted filtration. Owing to its higher hydrophilicity, negatively charged surface, and lower molecular weight cutoff, the Ti₃C₂T_X MXene-coated membrane showed great performance for the treatment of organic contaminants. Humic acid (HA)/tannic acid mixtures were selected as the target natural organic matter (NOM). Owing to weakened hydrophobic interaction and improved size exclusion upon using Ti₃C₂T_X MXene, it was difficult for HA to pass through the membrane. Membrane performance was tested for two different charged pharmaceuticals (amitriptyline and ibuprofen) under three pH conditions. The water permeabilities of pure water and both pharmaceuticals showed similar trends. This indicates that separation is affected by electrostatic interactions because the membrane surface is more negatively charged after Ti₃C₂T_X MXene coating. Additionally, the reusability of the Ti₃C₂T_X MXene-coated membrane was evaluated in three filtration cycles for NOM. After the first and second cleanings, recoveries of water permeabilities were 95.5% and 91.6% for HA. Although NOM can act as a foulant, HA caused reversible fouling. These findings indicate that the Ti₃C₂T_X-coated membrane can be engineered to effectively treat various organic contaminants with high water permeability, retention performance, and antifouling capability.