Design of Cu2O-Au composite microstructures for surface-enhanced Raman scattering study

Octahedral Cu2O-Au composite microstructures (CMSs) were synthesized with a facile in situ method and were attempted as surface-enhanced Raman scattering (SERS) substrates. The density of the Au nanoparticles (NPs) on the surface of the octahedral Cu2O microcrystals,can be controlled by tuning the concentration of the gold precursor, which can further influence the SERS activity of the Cu2O-Au CMSs system. The CMSs system exhibited a charge transfer from Au to Cu2O. Furthermore, metallic NPs deposited on the semiconductor material formed a local electromagnetic field, which altered the interfacial charge distribution. The SERS signal enhancement from the Cu2O-Au CMSs system is attributed to a combination of electromagnetic and chemical enhancement mechanisms occurring simultaneously at the semiconductor-metal interface. Overall, the proposed CMSs system will provide a new model for SERS study and application. (C) 2016 Elsevier B.V. All rights reserved.