Antenna Effect in Noble Metal‐Free Dye‐Sensitized Photocatalytic Systems Enhances CO2‐to‐CO Conversion

Dye‐sensitized photocatalytic systems (DSPs) have been extensively investigated for solar‐driven hydrogen (H2) evolution. However, their application in carbon dioxide (CO2) reduction remains limited. Furthermore, current solar‐driven CO2‐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 CO2‐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). Efficient CO2‐to‐CO dye‐sensitized photocatalytic systems are obtained by utilizing noble metal‐free photosensitizer (zinc‐porphyrin) and catalyst (cobalt‐quaterpyridine) derivatives. Upon introducing an additional chromophore (Bodipy), an antenna effect enhanced the photoproduction leading to 42.1 mmol g−1 h−1 of CO and 759 turnover numbers.