789305.fig.004a
(a)
789305.fig.004b
(b)
789305.fig.004c
(c)
789305.fig.004d
(d)
Figure 4: FESEM micrographs of MnO2 thin films on Ni-coated PET films at deposition duration of (a) 1 min, before, (b) 1 min, after, and (c) 60 min, before, (d) 60 min, after calcination at 200°C in air for 1 hour.