Great surface-enhanced Raman scattering in hybrids consisting of graphene and silver nanoparticles with large particle sizes

摘要

We have prepared graphene-veiled-nanoparticle hybrids by depositing a bilayer graphene film on silver nanoparticles with large particle sizes, ～200 nm. The hybrids possess good thermal stability and exhibit great surface-enhanced Raman scattering with enhancement factors of 49- and 21-fold for the G and 2D peaks, respectively. The electrical and optical absorption measurements revealed the occurrence of charge transfer and strong interactions between the silver nanoparticles and graphene. Accordingly, a possible mechanism of Raman enhancement is proposed for the present hybrids. This work demonstrates a well-designed way to improve surface-enhanced Raman scattering in graphene-based materials.