Figure 5.

a SEM image of V₂O₅–SnO₂ double-shelled nanocapsules. Inset shows the schematic structure of these double-shelled nanocapsules. The red spheres represent SnO₂ nanocrystals and the green double shells represent the V₂O₅ matrix; b low-magnification TEM images; c, d high-magnification TEM images indicate that the porous shell consists of a great deal of nanocrystals with the thickness of R₁ ≈ R₂ = 90 nm; e–g HRTEM images revealing lattice planes of V₂O₅ matrix and SnO₂ nanocrystals; h SAED pattern taken from individual nanocapsules which shows that these nanocapsules are polycrystalline. Reproduced with the permission of American Chemical Society from [46]