Composite materials based on covalent organic frameworks for multiple advanced applications

Abstract

Covalent organic frameworks (COFs) stand for a class of emerging crystalline porous organic materials, which are ingeniously constructed with organic units through strong covalent bonds. Their excellent design capabilities, and uniform and tunable pore structure make them potential materials for various applications. With the continuous development of synthesis technique and nanoscience, COFs have been successfully combined with a variety of functional materials to form COFs-based composites with superior performance than individual components. This paper offers an overview of the development of different types of COFs-based composites reported so far, with particular focus on the applications of COFs-based composites. Moreover, the challenges and future development prospects of COFs-based composites are presented. We anticipate that the review will provide some inspiration for the further development of COFs-based composites.

Keywords: COFs‐based composites; advanced applications; covalent organic frameworks.

FIGURE 1

A) Number of publications of covalent organic frameworks (COFs) and COFs‐based composites according to the Web of Science (data obtained 2021). B) Typical examples of COFs‐based composites.

FIGURE 2

A) Pd nanoparticles (NPs)/Pt NPs confined in thioether‐containing covalent organic frameworks (COFs) and their catalytic applications. Adapted with permission.^{[ 24 ]} Copyright 2017, American Chemical Society. B) Broad‐scope NPs@phos‐COFs and their multiple catalytic reactions. Adapted with permission.^{[ 47 ]} Copyright 2020, WILEY‐VCH. C) Synthesis of (Pd/C)@TpPa COFs. Adapted with permission.^{[ 51 ]} Copyright 2021, Elsevier.

FIGURE 3

A) The construction of COF‐Au nanoparticles (NPs) for colorimetric detection of Hg²⁺. Adapted with permission.^{[ 69 ]} Copyright 2019, Elsevier. B) The preparation of the TB‐Au‐COFs‐Ab₂ labels and the construction of the sandwich‐type electrochemical immunosensor. Adapted with permission.^{[ 70 ]} Copyright 2018, Elsevier. COF, covalent organic framework.

FIGURE 4

Schematic illustration of covalently linked various semiconductor‐COF Z‐Scheme photocatalysts. Adapted with permission.^{[ 96 ]} Copyright 2020, American Chemical Society. COF, covalent organic framework.

FIGURE 5

A) Schematic illustration for the synthesis of the MCNC@COF‐GSH. B) Workflow of N‐linked glycopeptide enrichment. Adapted with permission.^{[ 112 ]} Copyright 2019, American Chemical Society. COF, covalent organic framework.

FIGURE 6

Schematic illustration of the synthetic process of COF‐Au‐MnO₂‐HA and the therapeutic mechanism. Adapted with permission.^{[ 123 ]} Copyright 2021, Elsevier. COF, covalent organic framework.

FIGURE 7

A) The synthesis procedure for covalent organic framework (COF)/rGO. B) N₂ adsorption‐desorption isotherms of rGO, COF/rGO, and COF. C) A photograph of an ultralight COF/rGO aerogel standing on a leaf. D) The galvanostatic charge‐discharge curves of COF/rGO at a current density of 0.5, 1, 2, 3, and 4 A g⁻¹. E) The cyclic stability of COF/rGO at a current density of 8 A g⁻¹. Adapted with permission.^{[ 125 ]} Copyright 2020, Nature Publishing Group.

FIGURE 8

A) Preparation and B) contribution of COF@CNTs in capacity. Adapted with permission.^{[ 29 ]} Copyright 2018, Nature Publishing Group. COF, covalent organic framework.

FIGURE 9

The formation process of CTFs@MoS₂. Adapted with permission.^{[ 164 ]} Copyright 2019, Wiley‐VCH Verlag GmbH&Co.

FIGURE 10

A) Schematic diagram of covalent organic framework (COF)/Mn‐metal organic framework (MOF) hybrid. B) The 3D structure of Mn‐MOF. C) The interlinked COF and Mn‐MOF units based on the Mn‐N interaction along the c–direction with the bonding distance of ≈0.227 nm. D) Side views of the COF/Mn‐MOF hybrid. Adapted with permission.^{[ 195 ]} Copyright 2019, Wiley‐VCH Verlag GmbH&Co.

FIGURE 11

A) Schematic diagram of MOF@COF‐LZU1 synthesis. B) Cyclic voltammetry curve of a) MOF‐UiO‐66‐NH₂, b) MOF@COF‐LZU1, c) aza‐MOF@COF, d) areal capacitance, e) capacitance retention, and f) Nyquist electrochemical impedance spectra. Adapted with permission.^{[ 196 ]} Copyright 2020, Wiley‐VCH Verlag GmbH&Co. COF, covalent organic framework. MOF, metal organic framework.

FIGURE 12

A) Synthetic process of PCN‐222‐Co@TpPa‐1. B) SEM image of PCN‐222‐Co@TpPa‐1. C) TEM image of PCN‐222‐Co@TpPa‐1. Adapted with permission.^{[ 172 ]} Copyright 2019, Royal Society of Chemistry.

FIGURE 13

A) Schematic diagram of synthesizing metal organic framework (MOF)/covalent organic framework (COF)‐x hybrid materials. B) UV–vis diffuse reflectance spectra and C) the corresponding Tauc plots (the intersection of the dashed lines with the x–axis indicates the value of the optical band gap) of NH₂‐UiO‐66, TAPT‐TP‐COF, and MOF/COF‐50. Reproduced with permission.^{[ 209 ]} Copyright 2021, American Chemical Society.

FIGURE 14

Illustration of BMCAP nanocapsules for microwave dynamic thermotherapy (MWDT‐MWTT) and anti‐angiogenesis in colorectal cancer. Reproduced with permission.^{[ 197 ]} Copyright 2019, Elsevier.

FIGURE 15

A) 1) Synthesis of covalent organic framework (COF)‐DhaTab by the Schiff base reaction of Dha and Table 2. Schematic representation of trypsin adsorption in COF‐DhaTab. Adapted with permission.^{[ 222 ]} Copyright 2015, Nature Publishing Group. B) 1) Graphic view of lipase PS and porous materials used for the immobilization of enzymes; 2) Enzyme uptake capacity of various porous materials after incubation in lipase PS solution (30 mg mL⁻¹) for 6 h. Adapted with permission.^{[ 224 ]} Copyright 2018, American Chemical Society. C) Stepwise approach to construct biomacromolecule@capsule. Adapted with permission.^{[ 181 ]} Copyright 2020, American Chemical Society.

FIGURE 16

Schematic illustration of the nanocomposites fabrication, drug delivery, and in vivo combinative antitumor therapy. Adapted with permission.^{[ 229 ]} Copyright 2019, American Chemical Society.

FIGURE 17

The process for preparing TpPa/PSF membranes via IP. A) Schematic representation of the TpPa/PSF composites membrane. B) Physical appearance of the obtained TpPa/PSF composites membrane. Adapted with permission.^{[ 31 ]} Copyright 2019, Elsevier.

FIGURE 18

Synthesis of β‐ketoenamine‐kinked covalent organic frameworks (COFs) and hybridization with NH₂‐MXenes. Adapted with permission.^{[ 234 ]} Copyright 2020, American Chemical Society.