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

• Published in: Journal of alloys and compounds 2017-12, Vol.727, p.970-977
• Main Authors: Fahami, Abbas, Duraia, El-Shazly M., Beall, Gary W., Fahami, Mohammad
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Bayer process; Ca/Al layered double hydroxide; Chemical synthesis; Crystal structure; Crystallinity; Diffraction; Electron microscopy; Energy transmission; Field emission microscopy; Fourier transforms; Gibbsite; Hydroxides; Ion concentration; Mechanochemistry; Nanoparticles; Rietveld refinement; Scanning electron microscopy; Slaked lime; Studies; Thermal decomposition; Thermogravimetric analysis; Water treatment; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.08.212

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. •Hydrocalumite was synthesized by one-pot mechanochemistry method.•Structural characteristics of products were influenced strongly by ion substitutions.•XRD-Rietveld and FTIR spectra suggested predominant hydrocalumite in midrange.•Product showed hexagonal layered structure with lateral dimension around 397 nm.