Ultrasonically-enhanced preparation, characterization of CaFe-layered double hydroxides with various interlayer halide, azide and oxo anions (CO32-, NO3-, ClO4-)

Márton Szabados; Gábor Varga; Zoltán Kónya; Ákos Kukovecz; Stefan Carlson; Pál Sipos; István Pálinkó

doi:10.1016/j.ultsonch.2017.08.041

Ultrasonically-enhanced preparation, characterization of CaFe-layered double hydroxides with various interlayer halide, azide and oxo anions (CO₃^2-, NO₃^-, ClO₄^-)

Ultrason Sonochem. 2018 Jan;40(Pt A):853-860. doi: 10.1016/j.ultsonch.2017.08.041. Epub 2017 Sep 1.

Authors

Márton Szabados¹, Gábor Varga¹, 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, University of Lund, 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: 28946496
DOI: 10.1016/j.ultsonch.2017.08.041

Abstract

An ultrasonically-enhanced mechanochemical method was developed to synthesize CaFe-layered double hydroxides (LDHs) with various interlayer anions (CO₃^2-, NO₃^-, ClO₄^-, N₃^-, F^-, Cl^-, Br^- and I^-). The duration of pre-milling and ultrasonic irradiation and the variation of synthesis temperature in the wet chemical step were investigated to obtain the optimal parameters of preparation. The main method to characterize the products was X-ray diffractometry, but infrared and synchrotron-based X-ray absorption spectroscopies as well as thermogravimetric measurements were also used to learn about fine structural details. The synthesis method afforded successful intercalation of the anions, among others the azide anion, a rarely used counter ion providing a system, which enables safe handling the otherwise highly reactive anion. The X-ray absorption spectroscopic measurements revealed that the quality of the interlayered anions could modulate the spatial arrangement of the calcium ions around the iron(III) ions, but only in the second coordination sphere.

Keywords: CaFe-LDH; Interlayered halide, azide, oxo anions; Mechanochemical treatment; Ultrasonic irradiation; XAS−TG−IR.