A layered lead halide framework intercalated with Ru(bpy)₃ for efficient CO₂ photoreduction

Area of Science:

• Materials Science
• Photocatalysis
• Inorganic Chemistry

Background:

• Three-dimensional lead halide hybrids offer excellent photophysical properties but lack stability.
• Two-dimensional layered lead halides provide stability but have limited charge transport due to strongly bound excitons.

Purpose of the Study:

• To create a stable, efficient photocatalyst for CO2 reduction by covalently intercalating a photosensitizer into a layered lead halide framework.
• To investigate the mechanism of enhanced CO2 photoreduction in the novel hybrid material.

Main Methods:

• Covalent intercalation of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+) into [Pb23X42]4+ (X=Cl or Br) layered lead halide frameworks.
• Characterization of the hybrid material's structure and photophysical properties.
• Evaluation of photocatalytic CO2-to-CO reduction efficiency and mechanistic studies.

Main Results:

• The resulting hybrid material exhibits nearly full visible-light absorption and efficient photoinduced charge transfer.
• Achieved efficient CO2-to-CO photoreduction with an apparent quantum efficiency of ~3.0% at 500 nm.
• Demonstrated enhanced charge transport to Pb2+ sites, facilitating CO2 activation and reducing reaction barriers.

Conclusions:

• The covalent intercalation strategy yields a robust and highly efficient organolead halide photocatalyst.
• The [Ru(bpy)3]2+ ligands play a crucial role in improving charge transport and CO2 activation.
• This work presents a new paradigm for designing advanced layered lead halide photocatalysts.