Studies on Surface Plasmon Resonance of Noble Metallic Nanoparticles

The optical absorption spectra of Ag nanoparticles/silicate glass composites,Cu nanoparticles/silicate glass composites and Ag-Cu nanoparticles/silicate glass composites were theoretically calculated respectively by modified Mie theory.The results show that the surface plasmon resonance（SPR） peak of Ag nanoparticles locates at 425nm in Ag nanoparticles/silicate glass composites,which does not shift with the size of Ag nanoparticles changing.In addition,although the SPR peak of Cu nanoparticles in Cu nanoparticles/silicate glass composites is weak,it does not shift.In Cu-Ag core-shell nanoparticles/silicate glass composites,however,the SPR peak of Ag nanoparticles is red-shifted with the thickness of Ag shell increasing,while the SPR peak of Cu nanoparticles does not shift yet.In addition,Ag-Cu bimetallic nanoparticles/silicate glass composite materials were fabricated by two-step ion-exchange,experimental results show that as the size of Ag nanoparticles increases during ion-exchanged process under the same thermal treatment condition,the SPR peaks are red-shifted which agrees well with the calculated results.