Precisely Constructing Molecular Junctions in Hydrogen-Bonded Organic Frameworks for Efficient Artificial...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Artificial photosynthesis aims to mimic natural processes for sustainable fuel production.
• Key challenges include enhancing charge separation and material oxidation capabilities.

Purpose of the Study:

• To design and synthesize a molecular junction-type porphyrin-based crystalline photocatalyst.
• To improve the efficiency of converting carbon dioxide (CO2) and water into fuels and oxygen.

Main Methods:

• Self-assembly of a nickel porphyrin complex (reduction site) and pyridyl porphyrin (oxidation site) via hydrogen bonding and π-π stacking.
• Characterization of the crystalline structure and photocatalytic performance.
• Investigation of structure-function relationships using femtosecond transient absorption spectroscopy and density functional theory (DFT) calculations.

Main Results:

• The synthesized Ni-TCPP-TPyP material exhibits a highly crystalline structure with inherent molecular junctions.
• Efficient photogenerated charge separation and transport were observed.
• Achieved a CO production rate of 309.3 μmol g⁻¹ h⁻¹ with ~100% selectivity, significantly outperforming single-component catalysts and existing organic photocatalysts, without sacrificial agents.

Conclusions:

• The novel molecular junction design effectively enhances photocatalytic activity for CO2 conversion.
• This work offers insights into designing advanced artificial photocatalysts for clean fuel production.
• Paves the way for solar-driven renewable fuel generation through CO2 utilization.