Mimicking Overall Photosynthesis by Incorporating Paired Ce(III) Single-Atom Sites Into Covalent Organic Framework

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Artificial photosynthesis aims to mimic natural processes for sustainable chemical production.
• Developing efficient photocatalysts for both water oxidation (WOR) and CO2 reduction (CO2RR) remains a significant challenge.
• Existing photocatalysts often lack the necessary active sites, light absorption, or band structure for efficient overall photosynthesis.

Purpose of the Study:

• To design and synthesize a novel 3D covalent organic framework (COF) with integrated single-atom sites for artificial photosynthesis.
• To investigate the catalytic performance of the developed material for the conversion of CO2 and H2O into valuable chemicals.
• To understand the structure-activity relationship governing the photocatalytic efficiency.

Main Methods:

• Synthesis of a 3D COF, BPDA-AmCOF-Ce, featuring paired Ce(III) single atomic sites and pyrene moieties.
• Characterization of the COF's structure, including its bcu topology and interatomic distances.
• Photocatalytic experiments for CO2 and H2O conversion under visible light irradiation (λ > 420 nm).

Main Results:

• The synthesized BPDA-AmCOF-Ce exhibited excellent photocatalytic activity for converting CO2 and H2O.
• High production rates for CH3COOH (166.67 µmol g-1 h-1) and H2O2 (601.42 µmol g-1 h-1) were achieved with up to 94.4% selectivity.
• The catalyst demonstrated efficient visible light absorption and a suitable band structure for the overall photosynthetic process.

Conclusions:

• The developed 3D COF, BPDA-AmCOF-Ce, effectively mimics overall photosynthesis.
• The paired single-atom sites and pyrene moieties are crucial for efficient CO2RR and WOR, respectively.
• Combining COFs with single-atom catalysts offers a promising strategy for designing advanced artificial photocatalysts.