Effects of ultrasonic irradiation on the synthesis, crystallization, thermal and dissolution behaviour of chloride-intercalated, co-precipitated CaFe-layered double hydroxide

Márton Szabados; Adél Anna Ádám; Zoltán Kónya; Ákos Kukovecz; Stefan Carlson; Pál Sipos; István Pálinkó

doi:10.1016/j.ultsonch.2019.02.024

Effects of ultrasonic irradiation on the synthesis, crystallization, thermal and dissolution behaviour of chloride-intercalated, co-precipitated CaFe-layered double hydroxide

Ultrason Sonochem. 2019 Jul:55:165-173. doi: 10.1016/j.ultsonch.2019.02.024. Epub 2019 Feb 26.

Authors

Márton Szabados¹, Adél Anna Ádám¹, Zoltán Kónya², Ákos Kukovecz³, Stefan Carlson⁴, Pál Sipos⁵, István Pálinkó⁶

Affiliations

¹ Department of Organic Chemistry, University of Szeged, Dóm tér 8, Szeged H-6720, Hungary; Material and Solution Structure Research Group, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary.
² Department of Applied and Environmental Chemistry, University of Szeged, Rerrich B. tér 1, Szeged H-6720, Hungary; MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, Rerrich B tér 1, Szeged H-6720, Hungary.
³ Department of Applied and Environmental Chemistry, University of Szeged, Rerrich B. tér 1, Szeged H-6720, Hungary.
⁴ MAX-IV Laboratory, Ole Römers väg 1, Lund SE-223 63, Sweden.
⁵ Material and Solution Structure Research Group, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary; Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged H-6720, Hungary.
⁶ Department of Organic Chemistry, University of Szeged, Dóm tér 8, Szeged H-6720, Hungary; Material and Solution Structure Research Group, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary. Electronic address: palinko@chem.u-szeged.hu.

PMID: 30853533
DOI: 10.1016/j.ultsonch.2019.02.024

Abstract

The output power (30-150 W) and the periodicity (20-100%) of ultrasound emission were varied in a wide range to regulate and improve the crystallization process in the commonly used co-precipitation technique of chloride-intercalated CaFe-layered double hydroxides. The influence of ultrasound irradiation on the as-prepared materials was studied by X-ray diffractometry, dynamic light scattering, UV-Vis-NIR diffuse reflectance spectroscopy, specific surface area measurement, pore size analysis, ion-selective electrode potentiometric investigations and thermogravimetry. Additionally, structural alterations due to heat treatment at various temperatures were followed in detail by Fourier-transform infrared and X-ray absorption spectroscopies as well as scanning electron microscopy. The ultrasonic treatment was capable of controlling the sizes of primarily formed (from 19 nm to 30 nm) as well as the aggregated (secondary) particles (between 450 nm and 700 nm), and thus modifying their textural parameters and enhancing the incorporation of chloride anions into the interlamellar space. For the first time, the optical energy gap of CaFe-LDH was reported here depending on the nature of applied stirring (4.18-4.34 eV). The heat-treatment investigations revealed that the layered structure was stabile until 200 °C, even at the atomic level.

Keywords: CaFe-layered double hydroxide; Characterization with a range of instrumental techniques; Dissolution and thermal behaviour; NEXAFS/EXAFS investigation; Sonocrystallization.