Selective Deposition of Catalytic Metals on Plasmonic Au Nanocups for Room-Light-Active Photooxidation of o-Phenylenediamine

Plasmonic hotspots can enhance hot charge carrier generation, offering new opportunities for improving the photo-catalytic activity. In this work, eight types of heteronanostructures are synthesized by selectively depositing catalytic metals at the different sites of highly asymmetric Au nanocups for the photocatalytic oxidation of o-phenylenediamine. The oxidation of this molecule has so far mainly relied on the use of H2O2 as an oxidizing agent in the presence of an appropriate catalyst. The photocatalytic oxidation under visible light has not been reported before. The Au nanocups with AgPt nanoparticles grown at the opening edge and bottom exhibit the highest photocatalytic activity. The generated hot electrons and holes both participate in the reaction. The hot carriers from the interband and intraband transitions are both utilized. The optimal catalyst shows a favorable activity even under room light. Simulations reveal that the profound electric field enhancement at the hotspots boosts the hot-carrier density in the catalytic nanoparticles, explaining the overwhelming photocatalytic activity of the optimal catalyst.

Automated summary

Plasmonic hotspots can enhance hot charge carrier generation, offering new opportunities for improving the photo-catalytic activity. In this study, eight types of heteronanostructures were synthesized for the photocatalytic oxidation of o-phenylenediamine, with gold nanocups showing the highest activity. Simulations revealed that the electric field enhancement at the hotspots boosted the hot-carrier density in the catalytic nanoparticles.