Direct Formation of Mg–Al‐Layered Double‐Hydroxide Films on Glass Substrate by the Sol–Gel Method With Hot Water Treatment

Abstract

Amorphous Al 2 O 3 –MgO thin films with an Mg/Al ratio of unity were prepared on glass substrates by the sol–gel method with a heat treatment at 300°C for 30 min. By immersing the films in water containing sodium hydroxide (pH 10–13) at 100°C, nano‐crystals of Mg–Al‐layered double hydroxide (LDH) with a hexagonal structure, which is called hydrotalcite and the most basic composition of LDH, were precipitated on the amorphous Al 2 O 3 –MgO films. The maximum amount of Mg–Al nanocrystals was obtained when the film was immersed in basic solution of pH 12.