Pulsed laser synthesis of highly active Ag-Rh and Ag-Pt antenna-reactor-type plasmonic catalysts

Abstract

Ag, Pt, and Rh monometallic colloids were produced via laser ablation. Separate Ag-Rh and Ag-Pt heterostructures were formed by mixing and resulted in groupings of Rh/Pt nanoparticles adsorbing to the concavities of the larger Ag nanostructures. The 400 nm Ag plasmonic absorption peak was slightly blue-shifted for Ag-Pt and red-shifted for Ag-Rh heterostructures. Catalytic activity for the reduction of 4-nitrophenol increased significantly for Ag-Pt and Ag-Rh compared to the monometallic constituents, and persisted at lower loading ratios and consecutive reduction cycles. The enhancement is attributed to the Rh and Pt nanoparticles forming antenna-reactor-type plasmonic catalysts with the Ag nanostructures.