Electrostatic Attraction-Driven Assembly of a Metal-Organic Framework with a Photosensitizer Boosts Photocatalytic CO2 Reduction to CO

Reducing CO2 into fuels via photochemical reactions relies on highly efficient photocatalytic systems. Herein, we report a new and efficient photocatalytic system for CO2 reduction. Driven by electrostatic attraction, an anionic metal-organic framework Cu-HHTP (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) as host and a cationic photosensitizer [Ru(phen)(3)](2+) (phen = 1,10-phenanthroline) as guest were self-assembled into a photocatalytic system Ru@Cu-HHTP, which showed high activity for photocatalytic CO2 reduction under laboratory light source (CO production rate of 130(5) mmol g(-1) h(-1), selectivity of 92.9%) or natural sunlight (CO production rate of 69.5 mmol g(-1) h(-1), selectivity of 91.3%), representing the remarkable photocatalytic CO2 reduction performance. More importantly, the photosensitizer [Ru-(phen)(3)](2+) in Ru@Cu-HHTP is only about 1/500 in quantity reported in the literature. Theoretical calculations and control experiments suggested that the assembly of the catalysts and photosensitizers via electrostatic attraction interactions can provide a better charge transfer efficiency, resulting in high performance for photocatalytic CO2 reduction.

Automated summary

The new and efficient photocatalytic system Ru@Cu-HHTP, driven by electrostatic attraction, shows high CO2 reduction activity under laboratory light source or natural sunlight, with significantly reduced usage of photosensitizer compared to literature reports. The assembly of catalysts and photosensitizers via electrostatic attraction interactions provides better charge transfer efficiency for high performance in photocatalytic CO2 reduction.