Porphyrin and phthalocyanine based covalent organic frameworks for electrocatalysis

Covalent organic frameworks (COFs) are a burgeoning class of crystalline porous polymers. Owing to their unique features including tunable porosity, abundant accessible active sites, synthetically controllability, and pre-designed topological structures, COFs have been widely employed in various fields including catalysis, energy storage and conversion, gas adsorption, and optoelectronics. The incorporation of porphyrin (Por-) and phthalocyanine (Pc-) building units into COFs endows COFs with unique structural characteristics, excellent optical and electrical properties. Recent years have witnessed significant progress in reasonable design and construction of Por- and Pc-based COFs for electrocatalytic water splitting, CO2 reduction, and oxygen reduction. Herein, the synthetic strategies of Por- and Pc-based COFs are first summarized, which includes the rational design of building units and linkers, and the reaction types used in constructing Por- and Pc-based COFs. A systematic overview of the application of Por- and Pc-based COFs in the electrocatalytic reactions including CO2 reduction reaction (CO2RR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) are then performed. Lastly, the current challenges and directions to tailor Por- and Pc-based COFs for efficient and stable electrocatalysis are presented.