Chloride intercalated Zn-Al layered double hydroxide nanoparticles: novel photoluminescent colloids

The chloride intercalated Zn-Al Layered Double Hydroxides (LDH) synthesized by coprecipitation method followed by hydrothermal route manifest the unexpected photoluminescent properties in their colloids. Constant pH (approximate to 5) and the higher stirring rate were the extraneous factors which affect the LDHs particle size. Optimal Hydrothermal condition was found to be 70 degrees for 7 h. XRD analysis reveals the Rhombohedral phase and TEM reveals average particle size 5-6 nm of Zn-Al LDH. FEG-SEM depicts its hexagonal plate-like structure and EDS focus on the elemental composition of Zn and Al in it. Colloids were synthesized at room temperature by delamination of Zn-Al LDH nanoparticles in formamide. It was observed that Zn-Al LDHs in colloidal form shows photoluminescence because of its high surface area which facilitates molecular interaction with formamide and speeds up the recombination process of excited electron and holes. The study reveals that Photoluminescence of Zn-Al LDHs colloid depends on Zn-Al LDH particle concentration in their colloids.