Cu2O/Cu Chiral Catalysts for Highly Selective Solar‐Assisted CO2‐to‐CO Electroreduction

Abstract The intrinsic spin control capabilities of chiral materials help regulate the spin states of charge carriers, suppressing singlet‐state byproducts like H 2 and HCOOH while enhancing the Faradaic efficiency (FE) for CO. To induce strong chirality in transition‐metal‐based catalysts, intermediate organic molecules are utilized with extended chains in the chiral ligand complex to preserve chirality during hydrothermal synthesis. The resulting L ‐(‐)‐diethanolamine ( L ‐DEA) Cu 2 O/Cu chiral catalyst demonstrates high spin polarization efficiency, achieving a current density of −140 mA cm −2 at −1 V RHE , with a FE CO ​ exceeding 80%. Conversely, its FE H2 reduced to 1.6%. The L ‐DEA Cu 2 O/Cu chiral catalyst is subsequently integrated with a perovskite‐based photocathode and a BiVO 4 photoanode in a bias‐free tandem system. This artificial photosynthesis system demonstrates a solar‐to‐chemical efficiency ( η STC ) of 6.37% ( η STC ,CO of 4.49%), with a FE CO of 80%, maintaining stable operation for 14 h.