spired by green plant photosynthesis, the photocatalytic reduction of CO2 into hydrocarbons is a promising approach to solve the environmental problem of excess CO2 in the atmosphere. In addition to catalyst innovation, it is also necessary to develop a material combining multiple factors for economical CO2 reduction. Herein, we design Ag@P(IVBC-co-DVB) yolk–shell nanoparticles (AIDNPs) that possess an Agncore and an imidazolium functionalized polymeric shell. The Ag nanoparticles transform excellent visiblen light absorption into hot electron/hole pairs via surface plasmon resonance, pairs which are directlynshifted to the adsorbed CO2 on the polymeric shell owing to the suitable core-to-shell diffusion distance

of the material. As a result, CO2 is photoreduced to HCOOH with a competitive efficiency of 396 μmol gcat?1 h?1 in the absence of a photosensitizer or a sacrificial reducing agent. The investigation of the factors related to the photocatalytic CO2 production efficiency and the investigation of the photoelectric properties, as well as the proposed possible reduction mechanism provide a comprehensive model for efficient and economic CO2 photoreduction.