Metal–organic frameworks for water desalination

Rapid industrialization and ever-increasing global population culminate in continuous upsurge in freshwater crisis worldwide. The most reliable and promising solution to this crisis is utilizing sea-water as the freshwater source, and desalination technologies pave the way for efficient production of freshwater from sea-water. In this regard, membrane-based desalination method comes forth owing to its' efficient separation, operational ease, and low-energy consumption. Metal-organic frameworks (MOFs), the most explored crystalline porous materials, show tremendous promise as membrane-materials for desalination owing to their structural diversity, tunability, and porous voids which provide secondary water channels. Given significant advances are made in MOF-materials for desalination in the past few years, it is crucial to systematically summarize the recent progress and development of this field. In this review, a brief overview of various saline water systems and prerequisites for desalination are first presented. Then, advanced fabrication strategies MOF-membranes followed by the recent progress in MOF-materials for various desalination processes such as reverse osmosis and forward osmosis are systematically summarized. Finally, the authors' perspectives on the unsolved scientific and technical challenges and opportunities for MOF-integrated membranes toward real-world implementation are proposed. With further systematic development, MOF-materials promise to provide an ideal platform for next-generation desalination technology.