Synthesis and Growth Observation of Flower- and Spike-like Gold–Silver Nanoparticles

In this paper, we report a simple and reproducible synthesis of flower- and spike-like gold–silver (Au–Ag) nanoparticles. Reduction of aqueous solution of AgNO3 and HAuCl4 mixtures by L-ascorbic acid (AA) in the presence of poly(vinylpyrrolidone) (PVP) afforded the nanoparticles in a few minutes at room temperature. Stepwise trapping of the intermediate nanoparticles revealed the growth process of the petals of the flower-like nanoparticles from an initially formed nanoplate.