Fig. 2. (A) Is the TEM image of the prepared Ag core NPs; (B–D) are the TEM images of the prepared Ag@SiO₂ core–shell nanospheres at different magnifications; (E) TEM images of the core–shell structure and indicate the controlled SiO₂ shell thickness to be 2–5 nm; (F) corresponding to SAED patterns of the as-synthesized Ag@SiO₂ core–shell NPs which goes in agreement with the results from XRD; (G) EDS image of the prepared Ag@SiO₂ core–shell NPs; and (H and I) are the corresponding FESEM images of the prepared Ag@SiO₂ core–shell nanospheres.