Pd-Coated Au Triangular Nanoprisms as Catalysts for Hot-Carrier-Driven Photochemistry

Bimetallic nanoparticle dyads consisting of a plasmonic core and a catalytic metal shell have attracted significant attention in the context of solar-driven photocatalysts. However, a pertinent design considering both the optical properties of the core and shell and the thickness of the shell material is scarce. Through experiments and simulations, we demonstrated that the photo-catalytic efficiency of the Au triangular nanoprisms@Pd (AuTP@Pd) core@shell dyad largely depends on the thickness of the catalytic metal shell. For a lower thickness, the dyad showed LLIAJ enhanced photocatalytic activity compared to bare AuTPs. However, for a higher thickness, the dyad's catalytic activity reduced drastically and showed even lower catalytic activity than pristine AuTPs. From simulations, we showed that for a thin Pd layer, charge carriers were essentially generated at the Pd shell itself and thereby could be easily extracted and utilized. However, a thicker Pd shell screened the plasmonic core and reduced the charge-carrier formation. These findings will be relevant for the optimization of the bimetallic plasmonic catalyst design.