Figure 2. Particle size of SF-SAND was measured by TEM and AFM.

(a) TEM image of SF-SAND. The inset shows a corresponding high resolution TEM image. (b) The EDS spectrum of SF-SAND. (c) AFM topographic image of SF-SAND deposited on silicon (2 × 2 μm² scan). Inset: Topographic image (3D projection) and phase data (color scale) of two SF-SAND nanoparticles from (c) deposited on the silicon surface (150 × 150 nm²). (d) Particle size distribution of SF-SAND deposited on silicon from (c) is 4.52 ± 1.09 nm.