Facile synthesis and structural insight of chloride intercalated Ca/Al layered double hydroxide nanopowders

[摘要] Chloride intercalated Ca/Al layered double hydroxide (Ca/Al-Cl-LDH) was successfully synthesized by a one pot solvent-free mechanochemistry method. The effects of ion contents (0.1, 0.15, 0.2, 0.25, 0.3, 0.35, and 0.4) on phase compositions and structural features were evaluated by Rietveld analysis. The as-prepared specimens were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The XRD-Rietveld refinement results confirmed that the formation of high crystalline hydrocalumite was varied by incorporation of different ion contents. The characterization results demonstrated that pure hydrocalumite was the only crystalline phase in the midrange, while calcium hydroxide and gibbsite were appeared as additional phases with hydrocalumite at low and high Al substitutions, respectively. Detailed study of this phase behavior and structural trends was also scrutinized. Microscopic observations illustrated the hexagonal platelet-like shape of hydrocalumite powders with an average edge length of 397 nm. The thermal decomposition details of Ca/Al-Cl-LDH were scrutinized and reported. This unique approach offers an optimum ion concentration for the future design of Ca/Al-Cl-LDH framework that can be applied for numerous applications like biomedical and water treatment. (C) 2017 Elsevier B.V. All rights reserved.

[发布日期] 2017-12-15

[关键词] Ca/Al layered double hydroxide;Mechanochemistry;Rietveld refinement;Thermogravimetric analysis;Electron microscopy