Preparation of two-color photoluminescence emission based on azo dye-layered double hydroxide systems and controlling photoluminescence properties of Allura Red AC

The purpose of the present study was to synthesize types of organic-inorganic hybrid photofunctional materials and also to control their photoluminescence properties. Furthermore, we reported synthesis of a nanohybrid with two-color blue/violet and two-color red/yellow photoluminescence (PL) using the photofunctional anion (Allura Red AC) and Mg-Al-layered double hydroxide (LDH) nanosheets as the basic building blocks. The detailed chemical structure of the obtained composites was characterized by X-ray diffraction and infrared spectra (FT-IR). The results confirmed that Allura Red AC was successfully intercalated into the interlayer space of LDHs and the Allura Red AC-Mg3Al-LDH and Allura Red AC-Zn3Al-LDH hybrids were obtained with interesting photoemission properties. The PL analysis and diffuse reflectance spectroscopy (DRS) were used to study the photophysical properties. Allura Red AC-LDH systems exhibited a blue shift photo emission compared with the pristine Allura Red AC sample. Furthermore, Allura Red AC-Mg3Al-LDH exhibited superior photoluminous efficiency with a dual-color emission, while Allura Red AC and Allura Red AC-Zn3Al-LDH were one-color systems. Decreased band gap energy of Allura Red AC-LDH which is lower than that of Allura Red AC caused improved conductivity properties. Moreover, it was found from the DRS results that Allura Red AC-LDH could be regarded as the adsorbent electromagnetic wave and as a cover to protect materials against the electromagnetic waves. Therefore, this work provided a facile way for fabricating nanohybrids with two-color PL and controlling photoluminescent properties of the nanohybrids which had potential applications in the area of photoluminescent materials. [GRAPHICS]