Fabrication gallium/graphene core-shell nanoparticles by pulsed laser deposition and their applications in surface enhanced Raman scattering

We report our successful fabrication of a new gallium@graphene core-shell (Ga@G) nanostructure consisting of graphene grown on the surface of Ga nanoparticles (NPs) and its application as a high-performance substrate for surface enhanced Raman scattering (SERS). To our knowledge, this is the very first report to fabricate Ga@G NPs, particularly using a pulsed laser deposition (PLD) technique. The Raman results demonstrate that higher substrate temperature is beneficial for the formation of better quality graphene. Transmission electron microscopy (TEM) images reveal that Ga NP cores are completely encapsulated by the multi-layer graphene shell. More importantly, Ga@G NPs show significantly higher Raman signal for the absorbed Rhodamine 6G (R6G) molecules as compared to using the bare Ga NPs, validating the Ga@G NPs as a new type of SERS substrate. (C) 2014 Elsevier B.V. All rights reserved.