Enhancing the light absorption and dielectric properties of nitrate intercalated Zn-Al Layered double hydroxide through anionic exchange with ethylenediaminetetraacetate

Herein, we have reported a comparative study of two Zn-Al Layered double hydroxides (LDH) intercalated by nitrate (NO3-) and ethylenediaminetetraacetate (EDTA) ions, respectively. Indeed, nitrate-intercalated LDH was prepared by the coprecipitation method at a constant pH with Zn/Al = 2 (molar ratio), and used as a precursor for the synthesis of EDTA intercalated LDH through the anionic exchange method. Subsequently, these two LDH were analyzed by inductively coupled plasma, characterized by X-ray diffraction, thermogravimetric analysis and three spectroscopic techniques: Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy and impedance spectroscopy. The exchange of nitrate ions by EDTA led to a decrease in the electrical conduc-tivity, dielectric constant and dielectric loss tangent, and revealed an important increase in the absorption coefficient in UV-Vis-NIR range, with a large gap energy of approximately 6.30 eV. This work demonstrates the advantage of EDTA ions in decreasing the dielectric dissipation energy, and improving the light absorption of LDH compound.