Self-assembled intercalation of 8-hydroxyquinoline into metal ions exchanged magadiites via solid-solid reaction and their optical properties

Abstract

This study aimed at investigating the molecular level organization and photoluminescence in the interlayer space of magadiite (mag) synthesized by the process of solid-state intercalation. Host-guest composites were prepared by an easy grinding process without other operation. Detailed structural investigations were performed by powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Thermo-gravimetric analysis and differential thermal analysis (TGA/DTA), field emission scanning electron microscopy (FE-SEM), Ultraviolet-visible spectroscopy (UV–Vis), photoluminescence (PL) and inverted fluorescence microscope. Results confirmed that 8-hydroxyquinoline (8Hq) was intercalated in the interlayer space of mag in the presence of various metal ions (Ca2+, Zn2+ and Mn2+) inside. Basal spacings between silicate layers were controlled by exchanged metal ions and decorated 8Hq. Solid-state intercalation resulted in the lower proportion of intercalated 8Hq, but good luminescence was observed by PL. The complexes in the interlayer space showed special fluorescence properties. A speculative mechanism was proposed for reaction by solid-solid intercalation. This study provided a message for understanding the functional properties of composites 8Hq/Ca, Zn, Mn-mags, such as loading capacity and photoluminescence properties.