Metal–Semiconductor Heteronanocrystals with Desired Configurations for Plasmonic Photocatalysis

Precise control over the topology of plasmonic metal–semiconductor heteronanostructures is essential for fully harnessing their plasmonic function and hence for designing innovative solar energy conversion platforms. Here, we present a rational synthesis strategy for the realization of plasmonic metal–semiconductor heteronanocrystals with intended configurations through the site-selective overgrowth of semiconductor Cu₂O on desired sites of anisotropic Au nanocrystals. Both the exploitation of structural characteristics of Au nanocrystals and the selective stabilization of their surfaces are keys to the construction of heteronanocrystals with a specific configuration. Our approach can provide an opportunity to precisely explore the link between the solar energy conversion efficiency and the structure of heteronanocrystals as well as to obtain important insights into the underpinning mechanism. Heteronanocrystals produced by Cu₂O overgrowth preferentially on the multiple high-curvature sites of Au nanocrystals exhibited prominent photocatalytic hydrogen production activity due to efficient charge separation by strong plasmon excitation at the Au–Cu₂O interface and subsequent sustainable hot electron transfer from Au to Cu₂O