Photoactive Heteropore Covalent Metal-Organic Frameworks for CO2 Photoreduction

Area of Science:

• Materials Science
• Catalysis
• Environmental Science

Background:

• Metal-organic frameworks (MOFs) are investigated as photocatalysts for CO2 reduction.
• Existing strategies focus on enhancing MOF photocatalytic activity.
• Constructing photoactive heteropore MOFs for CO2 reduction remains an underexplored area.

Purpose of the Study:

• To synthesize and characterize novel 2D copper cyclic trinuclear unit (Cu-CTU)-based heteropore covalent MOFs (CMOFs).
• To evaluate the performance of these heteropore CMOFs in photocatalytic CO2 reduction reaction (CO2RR).
• To explore the synergistic effects of heteropore structures and photosensitive units on CO2RR.

Main Methods:

• Synthesis of two 2D Cu-CTU-based heteropore CMOFs and their homopore analogues.
• Characterization of CO2 uptake capacity.
• Photocatalytic CO2RR experiments using [Ru(bpy)3]Cl2 as a photosensitizer.
• Measurement of CO generation rate, selectivity, and apparent quantum yield (AQY).

Main Results:

• Heteropore CMOFs exhibited double the CO2 uptake compared to homopore analogues.
• Introduction of photosensitive units enhanced light harvesting and charge separation.
• Achieved a CO generation rate of 3548 μmol g-1 h-1 with 94.7% selectivity.
• Demonstrated a high AQY of 6.78% at 420 nm.
• Photoactive heteropore CMOFs showed high activity under diluted CO2 and natural sunlight.

Conclusions:

• Incorporating heteropore structures into MOFs enhances CO2 uptake.
• Combining heteropore design with photosensitive units synergistically boosts photocatalytic CO2RR performance.
• Developed MOFs show promise for efficient CO2 conversion under practical conditions.