fig4

Figure 4. (A) Schematic illustration of the synthesis of Janus heterodimers, (B) TEM image of Au-Ag Janus dimers and (C) STEM image with elemental mapping of an induvial Au-Ag Janus dimer^[86]. (D) Schematic illustration of the synthesis of Janus dimer on the surface of SiO₂ spheres, (E) TEM images with the structural model in the inset of SiO₂-Au@SiO₂ with different layer thicknesses of the additional SiO₂ layer and (F) TEM images with the structural model in the inset of SiO₂-Au dimers after growth of Au. The scale bars in (G and H) are 50 nm^[87]. (G) Schematic illustration of the synthesis of Au-Ag Janus@Au (solid) NPs and Au-Ag Janus@Au (hollow) NPs under different pH conditions and (H) STEM image with elemental mapping of Au-Ag Janus@Au (solid) nanoparticles^[89].