abstract
Magnesium-aluminium-bismuth-layered double hydroxides (LDH) intercalated with carbonate were studied in respect of maximal rate of substitution of Al3+ by Bi3+ for the first time. LDH with the nominal compositions of Mg3Al1 - x Bi (x) -CO3 (x = 0 to 0.5) were prepared using both the conventional super saturation co-precipitation method and sol-gel processing via hydration of the mixed oxide powders in carbonate-containing solutions. The mixed oxides were obtained either by calcination of the LDH (prepared by co-precipitation) or by using a novel alkoxide-free sol-gel method. All the LDH products were characterised using the methods of X-ray diffraction, scanning electron microscopy and thermogravimetry. The observed values of the lattice parameters of LDH phases were compared with the calculated values. It has been found that, regardless of the preparation method used and the conditions (pH, temperature, time) applied, the maximum rate of substitution of aluminium by bismuth in LDH is about 20 mol.%. A schematic representation of LDH structure of a 3R polytype [4, 5] where the lattice parameter c and the basal spacing d relate to each other as c = 3d. [GRAPHICS]
keywords
HYDROTALCITE-LIKE MINERALS; ANION-EXCHANGE REACTIONS; POLYTYPE DIVERSITY; INTERCALATION; ZN; CHEMISTRY
subject category
Materials Science
authors
Sokol, D; Salak, A; Ferreira, MGS; Beganskiene, A; Kareiva, A
our authors
Andrei Salak
Principal Researcher
Mário Guerreiro Silva Ferreira
Retired Professoracknowledgements
The work has been done in frame of the project TUMOCS. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 645660.