Comparison of nanostructures obtained from galvanic replacement in water and an ionic liquid for applications in electrocatalysis and SERS

We demonstrate potential applications for unusual dendrite like Au–Ag alloy nanoparticles formed via a galvanic replacement reaction in the ionic liquid [BMIM][BF4]. In comparison to Au–Ag alloy nanoshells synthesised via a similar reaction in water, the unusual branched structure of the dendritic materials led to increased electrocatalytic activity for the oxidation of both formaldehyde and hydrazine, and increased sensitivity and spectral resolution for the surface enhanced Raman scattering (SERS) of 4,4-bipyridal.

ToC synopsis: The galvanic replacement of Ag nanoparticles with [AuBr4]− ions in water and ionic liquid [BMIM][BF4] is performed and the electrocatalytic and SERS activity of the resultant hollow nanoshells and dendritic Au–Ag nanostructures is compared.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of dendritic Au–Ag nanostructures is achieved in the ionic liquid [BMIM][BF4].
► Comparisons are made between dendritic and hollow nanoshell Au–Ag nanostructures.
► Materials were examined for the electrochemical oxidation of formaldehyde and hydrazine.
► Materials were also examined for their surface enhanced Raman scattering properties.
► In both cases, the dendritic Au–Ag nanostructures out-performed the hollow Au–Ag nanoshells.