The influence of intercalated dye molecules shape and features on photostability and thermal stability between LDH layers

In the present work, an anionic azo dye, Orange G, was intercalated into the interlayer domain of Mg-Al layered double hydroxide (LDH) by co-precipitation route. The resulting hybrid material characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and thermal analysis, including thermal gravimetric analysis (TGA). The PXRD revealed the presence of host-guest interaction between the host matrix and interlayer anionic dye guest, with an expanded interlayer distance. The TGA studies showed that the dye-intercalated layered double hydroxides had higher thermal stability than the pristine dye. Scanning electron microscopy (SEM) method used to get information about the structure and morphology. Finally, photophysical properties of this intercalated hybrid measured by UV–visible diffuse reflectance (UV–VIS/DR) and photoluminescence spectroscopy (PL), which showed that intercalated dye to LDH had higher photostability than the pristine dye. Additionally, simulations studies were conducted using the Materials Studio software. There was a good agreement between calculated and measured X-ray diffraction patterns, and the results indicate that the dye molecules have vertical forms in the interlayer region. These values support to determine the relationship between the dye molecules translocation in the interlayer structure of LDH and thermal and photophysical stabilities of Orange G dye.