Tailored architectures in desalination membranes with MXene: Is this the way forward?

Just with one decade of history (The discovery of Ti 3 C 2 − 2011), studies on two-dimensional (2D) transition metal carbides, carbonatites, and nitrides (comprehensively stated as MXenes) vastly expanded from fundamental to applications level. The engineered MXenes are good competitors to 2D materials like graphene, metal–organic frameworks, etc., with widespread applications such as gas sensors, water purification, EMI shielding, energy storage, and catalysts etc. Owing to the 2D layered structure, the intercalation of cations, comprising multivalent ones and polar organic molecules, allows the control of interlayer distance and enables MXenes to be used in water purification and desalination. Besides, MXenes have a high aspect ratio due to the sheet structure, which provides nanochannels as diffusion paths for these applications. In this review, we explored the MXenes as membrane materials for pressure-driven membrane-based water desalination technology and the various physico-chemical modifications of MXene’s structure to enhance desalination performance. We also highlight membrane-desalination metrics, fabrication strategies of membranes, trade-off analysis, and the mechanisms behind enhanced performances due to modifications, which provide essential insights about these materials. Ultimately, we summarize the present challenges and provide the future outlook as the foundation for early researchers.