Microwave‐Assisted Solvothermal Synthesis of Covalent Organic Frameworks (COFs) with Stable Superhydrophobicity for Oil/Water Separation

COFs were synthesized by a microwave‐assisted solvothermal route, with the building blocks containing 1,3,5‐tris(4‐aminophenyl) benzene and 2,3,5,6‐tetra‐fluoroterephthalaldehyde (or 1,4‐phthalaldehyde). The −F groups introduced into the benzene ring promoted hydrophobicity and stability of the COFs. The universality and long effectiveness of oil adsorption can be realized when applying COFs as adsorbent. The powder also exhibited excellent water‐in‐oil emulsions separation performance, with the separation efficiency no lower than 99.5%. In this work, the use of microwave solvothermal synthesis of superhydrophobic COFs is potential to replace the conventional synthesis process and more suitable for industrial scale‐up production. Furthermore, the findings provide a new strategy for solving the problem of oil spill treatment and industrial water‐in‐oil emulsions separation by using the emerging 2D COFs. Covalent Organic Frameworks (COFs) for Oil/Water Separation: 2D Schiff base‐type COFs containing fluorine groups (−F) were prepared by a simple microwave‐assisted solvothermal method. Abundant −F groups bring superhydrophobicity and good stability to the structure of COFs. The superhydrophobic/superoleophilic COFs can be used in oil adsorption and separation of emulsified oil/water, providing a new strategy for pollution problems in oil spill treatment and industrial water‐in‐oil emulsions separation.