Recent advances of covalent organic framework-based nanozymes for energy conversion

The excellent stability and economic benefits of nanozymes have piqued researchers' interest as they represent a type of nanomaterials with enzyme-catalyzed capabilities. Among the various materials used as nanozymes, covalent organic frameworks (COFs) are favored by an extensive number of researchers as an emerging organic framework material because they can be rationally designed to mimic enzymes with desirable catalytic activities and have a high specific surface area and tunable pore structure. Therefore, in this paper, we provided a comprehensive overview of the advances of COFs-based nanozymes in which different construction strategies were involved, with special emphasis on heterogeneous synthesis methods, including pathways combining COFs with metal nanoparticles, enzymes, and metal organic frameworks, respectively. In addition, photocatalysis and electrocatalysis mechanism of COFs-based nanozymes in the field of energy conversion was discussed to conceive next-generation novelty applications of organic pollutants degradation, hydrogen production, antimicrobial, and anticancer therapy. Especially, the development of colorimetric and electrochemical sensors according to COFs-based nanozymes for sensing antioxidants, radioactive elements, antibiotics, and pesticide residues was also summarized. Finally, a brief discussion on the difficulties and potential applications of COFs-based nanozymes was held. We believe that this review can provide fresh perspective on the access of novelty COFs-based enzymes with user-defined high stability, and may bring about more intriguing applications.