Fig. 7From: Enhancement of Electrochromic Properties of Polyaniline Induced by Copper Ionsa The CV curves of Cu-doped PANI porous films measured in 0.5 M H2SO4 aqueous solutions with a scan rate of 50 mV/s sweeping between − 0.3 and 1.2 V. b The CA curves of 1st and 50th cycles and digital camera images of the PANI-0 and PANI-2 porous films at 0.5 V and − 0.25 VBack to article page