Shape transformation of gold nanoparticles in aqueous CTAB/CTAC solution to generate high-index facets for electrocatalysis and SERS activity

Gold nanoparticles (Au NPs) have demonstrated great potential in chemical and biological sensing, catalysis, biomedicine, X-ray computed tomography, and other applications, owing to their unique properties. Au NPs with high-index facets have attracted more attention in the past decade owing to their superior electrocatalytic activity in fuel cells and enhanced performance in surface-enhanced Raman spectroscopy (SERS) applications. This review presents an overview of our achievements in the direct synthesis of Au NPs with controlled shapes in water using cationic surfactants. By deliberately adjusting the nature of the surfactant stabilizers, preformed Au NPs with simple shapes can be readily transformed into Au NPs with complicated shapes with controlled high-index facets by simple seeded growth. The high-index facets of the as-prepared Au NPs can be consistently correlated with their superior performance in the electrooxidation of methanol and ethanol and their enhanced SERS activity.