Cascaded *CO−*COH Intermediates on a Nonmetallic Plasmonic Photocatalyst for CO2‐to‐C2H6 with 90.6 % Selectivity

Oxygen vacancies (O_V) in nonmetallic plasmonic photocatalysts can decrease the energy barrier for CO₂ reduction, boosting C1 intermediate production for potential C₂ formation. However, their susceptibility to oxidation weakens C1 intermediate adsorption. Herein we proposed a "photoelectron injection" strategy to safeguard O_V in W₁₈O₄₉ by creating a W₁₈O₄₉/ZIS (W/Z) plasmonic photocatalyst. Moreover, photoelectrons contribute to the local multi-electron environment of W₁₈O₄₉, enhancing the intrinsic excitation of its hot electrons with extended lifetimes, as confirmed by in situ XPS and femtosecond transient absorption analysis. Density functional theory calculations revealed that W/Z with O_V enhances CO₂ adsorption, activating *CO production, while reducing the energy barrier for *COH production (0.054 eV) and subsequent *CO-*COH coupling (0.574 eV). Successive hydrogenation revealed that the free energy for *CH₂CH₂ hydrogenation (0.108 eV) was lower than that for *CH₂CH₂ desorption for C₂H₄ production (0.277 eV), favouring C₂H₆ production. Consequently, W/Z achieves an efficient C₂H₆ activity of 653.6 μmol g^-1 h^-1 under visible light, with an exceptionally high selectivity of 90.6 %. This work offers a new strategy for the rational design of plasmonic photocatalysts with high selectivity for C₂₊ products.