Preparation of layered double hydroxide coating films via the aqueous solution process using binary oxide gel films as precursor

Layered double hydroxides (LDHs) are inorganic materials consisting of the hydroxide layers formed with at least two metallic elements and anions between the layers. In this study, we have investigated the functionalization of LDH coating films by modification of both sol-gel and aqueous solution processes. A binary oxide system, Al2O3-TiO2, was used for the precursor gel films. Judging from XRD and SEM measurements, LDH crystals were generated for the wide range of gel composition. Therefore, coating films with composite structure of Zn-Al LDH and TiO2 was obtained by simple process. The reconstruction of LDH, i.e., heat treatment and following incubation in aqueous solution, was also achieved. This process can be expected for the intercalation of functional molecules in LDH layers and crystallization of TiO2 for these composite coatings.