Combining metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs): Emerging opportunities for new materials and applications

In the past decades, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) basically enjoy the coordination chemistry and covalent chemistry, respectively, and such uniqueness has become the major obstacle hampering their further scope diversity and application multi-functionalization. Inspired from the principle of organic retrosynthesis, combining coordination bond and covalent bond together offers additional opportunities for constructing novel MOFs, COFs and MOF@COF hybrids as well as confer on them superior performances in versatile application fields. In this review, we firstly classify and summarize the recently reported synthesis strategies based on the integration of metal–ligand coordination and dynamic covalent bonds. Then, the application performances of as-constructed MOFs, COFs as well as MOF@COF hybrids are discussed and highlighted in the fields of adsorption, separation, catalysis, biosensing, energy storage and so on. Last, our personal insights of the remaining challenges and further prospects are also provided, in order to trigger much more inspirations and endeavors for this hot research field.