Fig. 4: Optimized plasmonic catalysis: efficient utilization of scattered photons.

a Schematic illustration of the gas-solid reaction, where mixed vapor of CO₂ and H₂O with centrally installed catalyst nanoparticles contained in a spherical reactor is illuminated with full-spectrum light. During the reaction, the scattered photons can be reflected to the catalyst surface, leading to efficient multi-absorption processes. b Average production rates of CH₄ through plasmon-induced CO₂RR using the gas-solid reaction device over Au rod@CuPd₂ under different CO₂ pressure and H₂O volume. The catalytic experiments are carried out in the mixed vapor of CO₂ and H₂O without any sacrificial agent under 400 mW cm^–2 full-spectrum light illumination. c, d The comparison of production rates (c, see Table S5) and AQEs (d, see Table S6) of Au rod@CuPd₂ reported in this work with the records reported in the literature for the last 5 years on artificial photosynthesis, which directly convert CO₂, H₂O and sunlight into compounds without sacrificial agent.