Staggered ABC-Stacking Cobalt-Triptycene Framework for Accelerating CO₂ Photoreduction.

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are promising photocatalysts due to tunable structures.
• Controlling MOF stacking, like staggered ABC-stacking, is challenging due to unfavorable energetics and weak π-π interactions.

Purpose of the Study:

• To synthesize a cobalt-triptycene MOF with a staggered ABC-stacking arrangement.
• To evaluate its performance as a photocatalyst for CO2 reduction.
• To elucidate the structure-activity relationships governing its catalytic efficiency.

Main Methods:

• Aqueous phase synthesis of cobalt-triptycene MOF.
• Experimental evaluation of photocatalytic CO2 reduction.
• Density functional theory (DFT) and molecular dynamics (MD) simulations.
• Principal component analysis (PCA) for structure-activity relationship analysis.

Main Results:

• Successful synthesis of ABC-stacking cobalt-triptycene MOF with 90% yield.
• Achieved a CO production rate of 4.43 mmol g⁻¹ h⁻¹, comparable to leading MOF photocatalysts.
• DFT/MD simulations showed lower activation energy for water, reduced Gibbs free energies for *COOH and *H intermediates.
• PCA identified Ik value, optical bandgap, and ΔG*H as key performance determinants, challenging the primacy of ΔG*COOH.

Conclusions:

• The ABC-stacking cobalt-triptycene MOF is a highly efficient photocatalyst for CO2 reduction.
• The study provides critical insights into MOF design principles for enhanced photocatalysis.
• Revises understanding of key factors influencing CO2 reduction efficiency in MOFs.