Recent Advances in the Preparation, Structural Modulation, and Applications of Metal–Organic Framework (MOF) Membrane Materials in the Field of Separation

ABSTRACT Metal–organic framework (MOF) membranes are a novel class of composite membranes. They use crystalline porous MOF materials as separation layers or functional fillers. Because of their well‐ordered and tunable pore structures and highly controllable chemical environments, MOF membranes show broad application prospects in gas separation, pervaporation, nanofiltration, ion sieving, and water treatment. This paper systematically reviews the fundamental characteristics, primary configurations, separation mechanisms, preparation methods, and structural regulation strategies of MOF membranes. It also covers their application progress in typical separation fields. First, based on the composition and structural features of MOFs, we summarize the advantages and limitations of four configurations: polycrystalline MOF membranes, mixed matrix membranes, two‐dimensional (2D) MOF layered membranes, and MOF glass membranes. The separation mechanism is then elaborated, which relies on the synergy between pore‐size sieving and chemical interactions. Second, we compare in detail the principles, applicable systems, and technical bottlenecks of various preparation methods. These include in situ growth, secondary growth, interface‐assisted growth, counter‐diffusion, vapor‐assisted conversion, and electrochemical deposition. On this basis, we systematically summarize the structural regulation strategies of MOF membranes from six aspects: crystal orientation, membrane thickness, defect engineering, intra‐pore chemical environment, interface engineering, and stability enhancement. Their influence on separation performance is also discussed. We emphasize the necessity of multi‐scale synergistic regulation. Furthermore, we present the latest research progress on MOF membranes for gas separation, pervaporation, nanofiltration, organic solvent nanofiltration, ion sieving, resource recovery, water treatment, and oil–water separation. Typical case studies are provided to analyze the structure’s performance relationship. Finally, we summarize the challenges currently faced by MOF membranes and present corresponding prospects. This paper aims to provide a systematic reference for the rational design and engineering application of MOF separation membranes.