  Surface plasmon resonance of metal nanostructures has broad application
prospects in the fields of photocatalysis, optical sensing, biomarkers and
surface-enhanced Raman scattering. This paper reports a graphene-assisted
method for preparing large-scale single crystal Ag(111) nanoparticle arrays
based on ion implantation technique. By surface periodic treatment and
annealing of the implanted sample, regularly arranged Ag nanoparticles can be
prepared on the sample surface. A new application for graphene is proposed,
that is, as a perfect barrier layer to prevent metal atoms from evaporating or
diffusing. All the Ag NPs show (111) crystal orientation. Besides, the Ag atoms
are covered by graphene immediately when they precipitate from the substrate,
which can prevent them from being oxidized. On the basis of this structure, as
one of the applications of metal SPR, we measured the Raman enhancement effect,
and found that the G peak of the Raman spectrum of graphene achieved about 20
times enhancement.
