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 H2 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) Cu2O/Cu chiral catalyst demonstrates high spin polarization efficiency, achieving a current density of −140 mA cm−2 at −1 VRHE, with a FECO​ exceeding 80%. Conversely, its FEH2 reduced to 1.6%. The L-DEA Cu2O/Cu chiral catalyst is subsequently integrated with a perovskite-based photocathode and a BiVO4 photoanode in a bias-free tandem system. This artificial photosynthesis system demonstrates a solar-to-chemical efficiency (ηSTC) of 6.37% (ηSTC,CO of 4.49%), with a FECO of 80%, maintaining stable operation for 14 h.