Well-Defined 2D Covalent Organic Polymers for Energy Electrocatalysis

Abstract

Highly efficient electrocatalysts are vital to meet energy and environmental challenges. Although numerous nonprecious metal or metal-free carbon-based catalysts have been demonstrated to entirely or partially replace noble-metal-based electrocatalysis, the absence of precise design and a predictable process hindered the development. Well-defined 2D covalent organic polymers (COPs) as a new exciting type of electrocatalyst presented superior potentials with precisely controllable capacities, such as robust tailoring heteroatom incorporation and location of active sites. Here we demonstrate the possibilities and potential of the well-defined 2D COPs used as highly efficient energy electrocatalysts for clean and renewable energy technologies. After surveying recent developments, we further discuss the possible future directions for designed synthesis of intrinsic COPs without carbonization to modulate active sites and the density of active sites at the molecular level. COP materials as a new family of electrocatalysts offer practical possibilities to study the structure, mechanism, and kinetics of energy electrocatalysis and may lead to a better solution for energy and environmental issues.

Covalent Organic Framework Electrocatalysts for Clean Energy Conversion

“…Extensive efforts and great progresses have been made toward the fabrication of electrocatalysts with earth‐abundant materials, including metals and their compounds (e.g., perovskite oxides, 3d transition metal oxides and dichalcogenides, and metal alloys), and metal‐free carbon nanomaterials (e.g., graphene, carbon nanotubes, nanoporous carbon). 2D covalent organic frameworks (COFs) are an emerging class of molecular frameworks linked by covalent bonds.…”

“…2D covalent organic frameworks (COFs) are an emerging class of molecular frameworks linked by covalent bonds. Although this COFs research field is still in its infancy, the unprecedented combination of large surface area, high crystallinity, tunable pore size, and unique molecular architecture has made COFs tantalizing targets for a new generation of electrocatalysts, photovoltaics, field‐effect transistors, light‐emitting diodes, selective transport, sensors, and drug delivery systems . COFs with precisely controllable structures can be constructed by selecting appropriate building blocks and linkage motifs, providing an ideal material system for efficient electrocatalysis.…”

Metal–Organic Frameworks Based Electrocatalysts for the Oxygen Reduction Reaction

“…The coordination between the metal centers and organic ligands determines largely the stability, while other factors determine the conductivity . Along this line, some MOFs such as porphyrin MOFs, phthalocyanine‐based conjugated MOFs and UiO family (UiO=Universitetet i Oslo) show great promise as pristine electrocatalysts towards ORR. Covalent organic frameworks, with complete organic skeletons, provide great opportunities to facilely construct porous pure carbon materials with the precise control over heteroatom doping More facile approaches for the synthesis of MOF‐based materials should be developed.…”

“…Covalent organic frameworks, with complete organic skeletons, provide great opportunities to facilely construct porous pure carbon materials with the precise control over heteroatom doping …”

“…ii)C ovalent organic frameworks,w ith complete organic skeletons,p rovide great opportunities to facilely construct porous pure carbon materials with the precise control over heteroatom doping. [132][133][134] iii)M ore facile approaches for the synthesis of MOF-based materials should be developed. Fore xample,p ostsynthetic modifications of metal nodes and ligands of MOFs,s uch as multi-metal coordination and solventassisted ligand incorporation, should be used to enrich the types of MOFs.…”