Formation of zinc oxide particles in cetyltrimethylammonium-smectites

Zinc oxide was prepared in the interlayer space of cetyltrimethylammonium-smectites (a natural montmorillonite and a synthetic saponite) by the reaction between the aqueous solutions of zinc chloride and sodium hydroxide in the presence of cetyltrimethylammonium-smectites. The products were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, as well as scanning electron, transmission electron, and optical microscopies. The formation of zinc oxide nanoparticles in the interlayer space of cetyltrimethylammonium-smectites was indicated by the transmission electron micrograph, diffuse reflectance absorption and the photoluminescence spectra. The photoluminescence of zinc oxide was affected by the interactions with cetyltrimethylammonium cation and silicate layer. The photoluminescence intensities of zinc oxide in cetyltrimethylammonium-saponite were higher than those in cetyltrimethylammonium-montmorillonite due to the quenching impurity in montmorillonite. Thus, the luminescence characteristics (both intensity and the energy) were controlled by the host–guest interactions with selection of host and modification.