Figure 3. SEM images of as-prepared Cu(OH)2 nanoneedles formed at 1.5 mA cm-2 in a 2.0 mol L-1 KOH solution at T = 28 ± 2 °C for different anodization times: (A) 300 s; (B) 500 s; (C) 1000 s; (D) 1500 s[88]. Reproduced from Ref.[88] with permission from the American Chemical Society.