Laser-assisted synthesis of Au-Ag alloy nanoparticles with tunable surface plasmon resonance frequency

摘要

Here we present our experimental results in synthesizing Au-Ag bimetallic nanoalloys with tunable localized surface plasmon resonance frequency through nanosecond laser-induced heating in the presence of polyvinyl alcohol as a reducing and capping agent via three different procedures: (i) Mixture of HAuCl4 and AgNO3 precursors, (ii) Mixture of Au nanoparticles (NPs) and AgNO3 precursor and (iii) Mixture of both Au and Ag NPs. Presence of single absorption band and direct dependence of the Au/Ag molar ratio to the shift of the absorption peak and lack of core-shell structure in Transmission Electron Microscope images confirms that the formed NPs are homogeneous alloys.