Au-Cu Dual-single-atom Sites on Bi2WO6 with Oxygen Vacancy for CO2 Photoreduction towards Multicarbon Products

CO2 photoreduction into high-value-added C2+ products struggles with energetic challenges in forming critical intermediates and multiple C−C bonds. Herein, an effectively synthesized photocatalyst, Bi2WO6 nanosheets with oxygen vacancies anchoring Au and Cu dual single atoms on the surface, can convert CO2 and H2O vapour into C3H6 and C2H4. The high product selectivity of 18.2% for C3H6 and 65.4% for total C2+ hydrocarbons are achieved under concentrated light irradiation (2.4 W·cm-2). Au-Cu dual-single-atom sites and defect engineering strategies exhibit synergistic effects on optimizing the reaction thermodynamics and charge kinetics for CO2 conversion. Theoretical calculations provide reference values for reaction pathways of C3H6 and C2H4 formation, with the C−C couplings being potential determining steps of multicarbon product formation. Our work offers a promising strategy with a combination of concentrated light irradiation technology and catalyst modification to achieve high selectivity of C2+ products.