MXene-based forward osmosis membrane for water treatment: Recent advances and future directions

Forward osmosis (FO) has attracted growing attention for desalination and wastewater treatment due to its low hydraulic pressure and energy demand. However, FO membranes still suffer from internal concentration polarization (ICP), reverse solute flux (RSF), and fouling. MXenes are considered promising candidates for membrane modification due to their hydrophilicity, tunable interlayer spacing, high surface area, and abundant surface functional groups. This mini-review provides a summary of recent advances in MXene-based FO membranes for water treatment applications. MXene synthesis routes are thoroughly discussed, revealing that top-down techniques remain the dominant approach. Key membrane modification strategies are then reviewed, including interlayer coating, mixed-matrix incorporation, and freestanding membrane formation. The review further evaluates the performance of pristine and modified MXene membranes, where existing studies reported improvements in water flux, enhancement in selectivity, control of RSF, ICP mitigation, and fouling resistance, particularly after the incorporation of modified MXene nanosheets. Recent applications of artificial intelligence and machine learning in FO membrane prediction and optimization are also discussed. Finally, major challenges and future directions are presented, including greener synthesis, leaching tests, evaluation of other MXene families, and life cycle assessment. Overall, this mini-review highlights the potential of MXene nanosheets in advancing FO membrane technology while identifying the key gaps that must be addressed for practical applications.