Fig. 6: EIS characterizations of the different intact/scratched coatings.

a Nyquist plots and b, c Bode plots of the intact pure EP and intact ZIF-8@Ca/EP coatings after 30 min of immersion in 3.5 wt.% NaCl solution. Nyquist plots and Bode plots of different d–f scratched pure EP and g–i scratched ZIF-8@Ca/EP coating during immersion in 3.5 wt.% NaCl solution for 60 d.