Metal-organic frameworks for gas sensors: comprehensive review from principal, fabrication to application

Gas sensors are valuable tools for human applications, and extensive research has been conducted in this field. However, practical implementation has yet to be fully realized. In response, efforts have been made to explore metal-organic frameworks (MOFs), a novel class of porous materials, as potential solutions. MOFs exhibit exceptional porosity and highly tunable chemical compositions and structures, giving rise to a wide range of unique physical and chemical properties. Significant progress has been achieved in developing MOF-based gas sensors, improving sensing performance for various gases. This review aims to provide a comprehensive understanding of MOF-based gas sensors, even for readers unfamiliar with MOFs and gas sensors. It covers the working principles of these sensors, fundamental concepts of MOFs, strategies for tuning MOF properties, fabrication techniques for MOF films, and recent studies on MOF and MOF-derivative gas sensors. Finally, current challenges, overlooked aspects, and future directions for fully exploiting the potential of MOFs in gas sensor development are discussed.