Microstructure-controlled synthesis of oriented layered double hydroxide thin films: Effect of varying the preparation conditions and a kinetic and mechanistic study of film formation

The microstructure-controlled synthesis of oriented layered double hydroxide (LDH) thin films on polystyrene substrates has been investigated in detail and the effect of varying the preparation conditions, such as the extent of sulfonation of the substrate, the total concentration of metal ions in the precursor solution, the temperature, and the reaction time are described. The kinetic features of the formation of the LDH films have also been derived; it was found that the best fit corresponds to a second-order exponential nucleation law. As a result, a possible mechanism for the formation of LDH films on the polystyrene substrate has been proposed, involving transportation of metal cations to the surface of the substrate, adsorption, and enrichment of the cations on the substrate, followed by nucleation and oriented growth of LDH films at the phase boundary.