RESUMEN
Oxygen vacancies (OV) 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 OV 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 OV enhances CO2 adsorption, activating *CO production, while reducing the energy barrier for *COH production (0.054â eV) and subsequent *CO-*COH coupling (0.574â eV). Successive hydrogenation revealed that the free energy for *CH2CH2 hydrogenation (0.108â eV) was lower than that for *CH2CH2 desorption for C2H4 production (0.277â eV), favouring C2H6 production. Consequently, W/Z achieves an efficient C2H6 activity of 653.6â 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.
RESUMEN
Solar-driven clean water production is challenged by VOCs (volatile organic compounds), which pose health risks in distilled water. Herein, we developed a Cu/W18O49@Graphene photothermal-photocatalytic material addressing VOCs contamination. Plasmonic coupling between Cu and W18O49 enhances light absorption, and 1-2 layers of graphene encapsulation protects oxygen vacancies within W18O49 while facilitating hot electron extraction, effectively mitigating their ultrafast relaxation. Density functional theory calculations revealed enhanced VOCs adsorption on graphene. These synergies address oxygen vacancy decay in W18O49 and provide more active sites for gas-liquid-solid triphase photocatalytic reactions. Integrated with a three-dimensional floating evaporator substrate, the optimized Cu/W18O49@Graphene material achieved an effective water evaporation rate of 1.41 kg m-2 h-1 (efficiency of 88.6%), exceptional stability (>120 h), and remarkable 99% phenol removal under 1 sun irradiation (1 kW m-2). This work provides a promising solution to mitigate VOCs contamination in solar-driven water evaporation.