The photograph of colloid (A), normalized UV–vis Abs. spectra (B). Inset of (B) is the plot of the Abs. peak against the Au mole ratio of various Au-Ag alloy NPs. a: pure Au (abs, absorption: 522 nm); b-d: Au-Ag alloy (abs: 489, 459, and 432 nm, respectively) synthesized at 120°C with the Au3+:Ag+ ratio of 1:10; e: pure Ag (abs: 410 nm).
Sun et al. Nanoscale Research Letters 2012 7:225 doi:10.1186/1556-276X-7-225