Cascaded *CO-*COH Intermediates on a Nonmetallic Plasmonic Photocatalyst for CO-to-CH with 90.6 % Selectivity.

Oxygen vacancies (O) in nonmetallic plasmonic photocatalysts can decrease the energy barrier for CO reduction, boosting C1 intermediate production for potential C formation. However, their susceptibility to oxidation weakens C1 intermediate adsorption. Herein we proposed a "photoelectron injection" strategy to safeguard O in WO by creating a WO/ZIS (W/Z) plasmonic photocatalyst. Moreover, photoelectrons contribute to the local multi-electron environment of WO, 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 enhances CO 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 *CHCH hydrogenation (0.108 eV) was lower than that for *CHCH desorption for CH production (0.277 eV), favouring CH production. Consequently, W/Z achieves an efficient CH activity of 653.6 μmol g h 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 C products.