Decoupling Interlayer Interactions Boosts Charge Separation in Covalent Organic Frameworks for High-Efficiency...

Area of Science:

• Materials Science
• Photocatalysis
• Computational Chemistry

Background:

• Covalent organic frameworks (COFs) show promise as photocatalysts due to their tunable properties.
• Previous research focused on narrow bandgaps, overlooking interlayer coupling's role in charge transfer.
• Monolayer models fail to capture essential interlayer effects on electron transport.

Purpose of the Study:

• Investigate the influence of interlayer interactions on intralayer charge transfer in imine-based COFs using DFT.
• Understand how interlayer coupling affects electron transport to catalytic sites.
• Design COFs with optimized interlayer interactions for enhanced photocatalysis.

Main Methods:

• Density functional theory (DFT) calculations.
• Theoretical analysis of bilayer COF architectures.
• Design and synthesis of isomeric pyrene-based COFs with varied interlayer coupling.

Main Results:

• Bilayer COFs exhibit significant interlayer interference in charge transfer, unlike monolayer models.
• Weakened interlayer interactions in pyrene-based COFs improved photocatalytic CO2 reduction.
• Achieved a CO evolution rate of 553.3 µmol g⁻¹ h⁻¹ with 94% selectivity under visible light.

Conclusions:

• Interlayer coupling is a critical factor in COF photocatalyst design.
• Optimizing interlayer interactions enhances charge transfer dynamics.
• This work provides a new principle for developing efficient COF-based solar energy conversion materials.