Effect of potential cycling in basic solutions on the structure of Ni–Al layered double hydroxide films

New reflections appear in the powder X-ray diffraction patterns of Ni–Al–Cl LDH films that have been subjected to repeated voltammetric scans in basic electrolytes (pH ⩾ 12). They are attributed to the formation of new phases, one of which is β-Ni(OH)2. The intensities of the d003 and d006 reflections of the LDH layer were also reduced. This was not observed for Ni–Al–Cl LDH films that were simply soaked in basic solutions or cycled in pH 8 buffer electrolyte solutions. The XRD pattern of Ni–Al–CO3 LDH films was not affected by voltammetric scanning in basic electrolyte.