Synthesis and characterization of dendritic and porous Ag–Pd alloy nanostructures

Dendritic and porous Ag–Pd alloy nanostructures were successfully fabricated on the surface of silicon substrate using the co-reduction method and galvanic replacement reaction, respectively. The molar compositions of Ag and Pd in the alloy could be modulated by controlling the molar ratios of metal precursors and reaction time. The Ag–Pd alloy nanostructures were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD). The morphology and phase of Au–Pd alloy nanostructures were discussed as a function of molar ratios of metal precursors and reaction time. In addition, the morphology and composition-dependent surface-enhanced Raman scattering (SERS) of the as-synthesized Ag–Pd alloy nanostructures were investigated. The SERS enhancement factor was estimated and SERS mapping was performed to prove the homogeneity of these substrates. The results indicate that as-synthesized dendritic and porous Ag–Pd alloy nanostructures are good candidates for SERS spectroscopy.

Graphical abstractAg-Pd alloy nanostructures with different morphologies were prepared and used as SERS substrates.Figure optionsDownload full-size imageDownload high-quality image (86 K)Download as PowerPoint slideHighlights► Dendritic and porous Ag–Pd alloy nanostructures were fabricated on the surface of silicon substrate by simple methods. ► Ag–Pd alloy nanostructures together with the silicon substrate can be directly used as SERS substrate to probe molecules. ► The dendritic and porous Ag–Pd nanostructures exhibit high SERS activity.