(a)
(b)
(c)
(d)
Figure 5: SEM photographs for PVAc/[Co(NH3)5Cl]Cl2 composite films with different concentrations of [Co(NH3)5Cl]Cl2: (a) 0 wt.%, (b) 3 wt.%, (c) 6 wt.%, and (d) 9 wt.%.