834184.fig.002a
(a)
834184.fig.002b
(b)
834184.fig.002c
(c)
834184.fig.002d
(d)
Figure 2: SEM images of the TiO2 nanoparticle film on FTO glass (a) vertical view; side view for spinning speed at (b) 800 rpm, (c) 500 rpm, and (d) 100 rpm.