427310.fig.003a
(a)
427310.fig.003b
(b)
427310.fig.003c
(c)
Figure 3: TEM micrograph of (a) SiO2/TiO2 nanoparticles, (b) Fe3O4/SiO2/TiO2 nanoparticles, and (c) EDX spectra of Fe3O4/SiO2/TiO2 core-shell nanoparticles.