The Cross‐Linking Mechanism and Applications of Catechol–Metal Polymer Materials

Abstract Catechol plays an important role in many systems by interacting with organic (e.g., amino acids) and inorganic (e.g., metal ions, metal oxides) compounds. Catechol cross‐linked polymer networks exhibit significant mechanical strength, good adhesiveness, and life‐like characteristics. Recently, catechol–metal coordination materials have aroused increasing interest in multifunctional applications. Numerous influential studies have demonstrated that the type of metal ions and the structure of phenolic (such as natural phenolic (e.g., tannic acid, gallic acid, and lignin) or synthetic catechol‐containing polymers) play important roles in the formation of catechol–metal coordination complexes. Although catechol–metal‐based materials have been successfully prepared, the cross‐linking chemistry between catechol and metal ions is still an important topic. To achieve catechol–metal‐based materials with controllable and superior performance like living organisms, an in‐depth understanding of the cross‐linking mechanism is crucial. This review summarizes some studies on the coordination of catechol–metal‐based materials, as well as the chemical mechanism behind the cross‐linking of metal ions and catechol‐containing molecules. The pathways and parameters that can affect the cross‐linking are also discussed. Their advanced applications in the energy strategy, environmental filtration, biomedical, mechanical, adhesive, and some emerging fields, together with the current trends are also explored.