Metal-containing covalent organic framework: a new type of photo/electrocatalyst

Metal-containing covalent organic frameworks (MCOFs), as a class of crystalline organic polymers with abundant single-atom metal sites, can respond effectively to various vital reactions, including hydrogen evolution reaction (HER), CO2 reduction reaction (CO2RR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The advent of MCOFs provides a platform for the establishment of model catalysts with highly repetitive structure to facilitate theoretical calculations and high-throughput screening while designing flexibility in monomer construction to lay the foundation for the development of highly selective and active photo/electrocatalysts. In this review, we summarize the recent progress in this field and highlight several important MCOFs photo/electrocatalysts for OER, ORR, HER, and CO2RR. Moreover, various approaches are also mentioned to improve or optimize the catalysts and indicate the future research direction on enhancing the performance of MCOFs catalysts based on the current existing challenges.