Regulating π-π Stacking Interactions to Boost Near-Infrared Light-Driven CO₂ Reduction

Area of Science:

• Materials Science
• Photocatalysis
• Green Chemistry

Background:

• Developing efficient near-infrared (NIR) light-driven photocatalysts for CO2 reduction is crucial for sustainable energy solutions.
• Existing photocatalysts often struggle with efficiency and stability under NIR irradiation.
• BODIPY-based materials offer potential for NIR light absorption and photocatalytic applications.

Purpose of the Study:

• To develop novel BODIPY-based π frameworks as efficient photocatalysts for NIR light-driven CO2 reduction.
• To investigate the role of π-π stacking interactions in enhancing photocatalytic activity.
• To achieve high efficiency in converting CO2 to formate (HCOO-) using visible light.

Main Methods:

• Synthesis of BODIPY-based π frameworks, including the optimized π-pyrenyl (π-PY) framework.
• Photocatalytic reduction of CO2 to HCOO- coupled with benzyl alcohol oxidation to benzaldehyde in aqueous solution under NIR light.
• Characterization of photocatalytic performance under varying CO2 concentrations (>99% and 15%).
• Utilizing experimental data and theoretical calculations to understand structure-activity relationships.

Main Results:

• The π-PY framework demonstrated superior photocatalytic activity for CO2 reduction, achieving high HCOO- production rates.
• Optimized π-π stacking interactions in π-PY significantly boosted charge separation, transfer, carrier lifetime, and reduced the energy gap.
• The π-PY framework exhibited HCOO- production rates of 4045 µmol g-1 h-1 (>99% CO2) and 1693 µmol g-1 h-1 (15% CO2).
• The π-PY framework represents a state-of-the-art photocatalyst for NIR-light-driven CO2 reduction.

Conclusions:

• BODIPY-based π frameworks are effective NIR photocatalysts for CO2 reduction.
• π-π stacking interactions play a critical role in enhancing photocatalytic efficiency by improving charge dynamics and reducing the energy gap.
• The π-PY framework offers a promising strategy for developing advanced photocatalysts for sustainable CO2 conversion.