Antenna Effect in Noble Metal-Free Dye-Sensitized Photocatalytic Systems Enhances CO 2 -to-CO Conversion.

Dye-sensitized photocatalytic systems (DSPs) have been extensively investigated for solar-driven hydrogen (H 2 ) evolution. However, their application in carbon dioxide (CO 2 ) reduction remains limited. Furthermore, current solar-driven CO 2 -to-CO DSPs typically employ rhenium complexes as catalysts. In this study, we have developed DSPs that incorporate noble metal-free components, specifically a zinc-porphyrin as photosensitizer (PS) and a cobalt-quaterpyridine as catalyst (CAT). Taking a significant stride forward, we have achieved an antenna effect for the first time in CO 2 -to-CO DSPs by introducing a Bodipy as an additional chromophore to enhance light harvesting efficiency. The energy transfer from Bodipy to zinc porphyrin resulted in remarkable stability (turn over number (TON)=759 vs. CAT), and high CO evolution activity (42 mmol g -1  h -1 vs. CAT).