Metalloporphyrin-Based Covalent Organic Frameworks: Design, Construction, and Photocatalytic Applications

Metalloporphyrin-based covalent organic frameworks (MPor-COFs) are emerging porous crystalline materials that combine the optoelectronic properties of metalloporphyrins with the highly ordered structure of COFs. Such a combination not only extends the light absorption spectrum of COFs by incorporating porphyrins but also improves the separation and transport capabilities of photo-generated electrons and holes by leveraging the structural advantages of organic frameworks. At the same time, the metal ions embedded in the porphyrin ring provide abundant active sites and optimize charge transfer channels, showing particular advantages in photocatalysis. The molecular design, construction, and photocatalytic application of MPor-COFs were reviewed in this paper. The intrinsic relationship among the structure, optoelectronic properties, and specific photocatalytic application received special attention. First, the role of the metal center in regulating the electronic structure and photophysical property of porphyrin monomers was introduced, as well as the impact of bond type on framework stability and charge transport efficiency. Then, the synthesis strategies for MPor-COFs were summarized. Finally, the applications of these materials in photocatalysis were critically reviewed, and their prospects and challenges in energy conversion and environmental remediation were also discussed.