Covalently connected core-shell NH₂-MIL-125@COFs-OH hybrid materials for visible-light-driven CO₂ reduction

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) are promising porous materials.
• Developing efficient photocatalysts for CO2 reduction is crucial for environmental sustainability.
• Hybrid materials offer synergistic properties for improved catalytic performance.

Purpose of the Study:

• To construct novel core-shell MOFs@COFs hybrid materials.
• To investigate the structure-property relationships for CO2 photocatalytic reduction.
• To explore the potential of these hybrid materials in sustainable energy applications.

Main Methods:

• Core-shell MOFs@COFs hybrid materials were synthesized using NH2-MIL-125 as the core and COF-OH as the shell.
• The thickness of the COF-OH shell was controlled by adjusting the feeding amount of NH2-MIL-125.
• The photocatalytic activity was evaluated by measuring CO2 reduction to CO under visible light irradiation.

Main Results:

• The NH2-MIL-125@COF-OH hybrid materials exhibited a type-II heterojunction structure.
• The hybrid materials showed enhanced photogenerated electron transfer and separation of electron-hole pairs.
• The NH2-MIL-125@COF-3 material achieved the highest CO yield (22.93 μmol·g⁻¹·h⁻¹), outperforming individual MOFs and COFs.

Conclusions:

• The core-shell MOFs@COFs hybrid materials demonstrate superior performance for CO2 photocatalytic reduction.
• The type-II heterojunction and interfacial CN covalent bonds are key to enhanced photocatalytic activity.
• This study provides valuable insights for designing advanced MOFs@COFs materials for CO2 utilization.