425071.fig.003a
(a)   Ag seeds
425071.fig.003b
(b) Ag-Au 10 min heating
425071.fig.003c
(c) Ag-Au 30 min heating
425071.fig.003d
(d) Ag-Au 60 min heating
Figure 3: Typical TEM images of (a) polygonal Ag seeds and ((b)–(d)) Ag-Au bimetallic products after heating Ag seeds/HAuCl4/PVP/EG solution for 10–60 min under O2 gas bubbling. Scale bars of TEM images (a) and (b) are the same as those of (c) and (d), respectively.