Porous Ag and Au hybrid nanostructures: Synthesis, morphology, and their surface-enhanced Raman scattering properties

In this paper, an ordered porous Ag and Au hybrid nanostructures were obtained by using ordered SiO2 nanospheres film as sacrificial templates. Different from previous reports, the different atom ratio of Ag and Au can be conveniently used to control film structures by simply varying the experimental conditions. The morphology of these nanostructures has been characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), and their performance as surface-enhanced Raman scattering (SERS) substrates has been evaluated by using rhodamine 6G (R6G) as probe molecule. It was found that the enhancement ability of the ordered porous Ag and Au hybrid nanostructures were related with the atom ratio of Ag and Au. The highest enhancement factor can be achieved at the average value of 4.76×109 from the sample when the atom ratio of Au/Ag is 1:1.