Inwardly Directed Linker Propagation: Constructing 3D Covalent Organic Frameworks for Efficient H₂O₂ Photosynthesis

Area of Science:

• Materials Science
• Chemistry

Background:

• The design of three-dimensional covalent organic frameworks (3D COFs) is limited, restricting their structural diversity and applications.
• Existing strategies often lead to planar frameworks, hindering the development of complex 3D architectures.

Purpose of the Study:

• To develop a novel inwardly directed linker propagation strategy for assembling 3D COFs.
• To investigate the structural differences and application potential of COFs synthesized with inwardly versus outwardly directed strategies.
• To enhance hydrogen peroxide (H2O2) production via photosynthesis using engineered COFs.

Main Methods:

• Proposed an inwardly directed linker propagation strategy for synthesizing COF-IN-1 and COF-IN-2.
• Synthesized outwardly directed expanded COFs (COF-OUT-1 and COF-OUT-2) for comparison.
• Characterized the topological structures (cpt vs. acs) and dimensionalities (2D vs. 3D) of the synthesized COFs.
• Evaluated the performance of the COFs in H2O2 photosynthesis and developed a biphasic system for continuous H2O2 production and extraction.

Main Results:

• Inwardly directed propagation yielded 3D COFs (COF-INs) with controlled triple entanglements and acs topology.
• Outwardly directed expansion resulted in planar 2D COFs (COF-OUTs) with cpt topology.
• The 3D COFs (COF-INs) significantly enhanced H2O2 photosynthesis compared to 2D COFs.
• A biphasic fluid system demonstrated continuous H2O2 photosynthesis and extraction.

Conclusions:

• The inwardly directed linker propagation strategy successfully expands the design possibilities for 3D COFs.
• Dimensional regulation of COF frameworks through linker directionality influences their application performance, particularly in H2O2 photosynthesis.
• This work provides a new avenue for creating advanced COFs with tailored properties for specific applications.