Line defects in plasmatic hollow copper ball boost excellent photocatalytic reaction with pure water under ultra-low CO concentration.

By using a low CO concentration as a C1 source, the design of a plasmonic catalyst that can effectively photocatalytic CO reduction is of great significance for sustainable and ecological development. Herein, the space confinement effect and liquid environment of the molten salt result in uniform hollow structure, while the strong aggressive force furnished via using molten salt enhances the formation of line defects. This special structure can not only provide a large number of active sites but also greatly accelerate the transport of photoinduced charge carriers.