Sonication accelerated formation of Mg-Al-phosphate layered double hydroxide via sol-gel prepared mixed metal oxides

Denis Sokol; Daniel E L Vieira; Aleksej Zarkov; Mário G S Ferreira; Aldona Beganskiene; Vasili V Rubanik; Aleksandr D Shilin; Aivaras Kareiva; Andrei N Salak

doi:10.1038/s41598-019-46910-5

Sonication accelerated formation of Mg-Al-phosphate layered double hydroxide via sol-gel prepared mixed metal oxides

Sci Rep. 2019 Jul 18;9(1):10419. doi: 10.1038/s41598-019-46910-5.

Authors

Denis Sokol¹, Daniel E L Vieira², Aleksej Zarkov¹, Mário G S Ferreira², Aldona Beganskiene¹, Vasili V Rubanik³, Aleksandr D Shilin³, Aivaras Kareiva⁴, Andrei N Salak⁵

Affiliations

¹ Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, LT-03225, Vilnius, Lithuania.
² Department of Materials and Ceramics Engineering and CICECO - Aveiro Institute of Materials, University of Aveiro, 3810-193, Aveiro, Portugal.
³ Institute of Technical Acoustics of National Academy of Sciences of Belarus, Lyudnikov Avenue, 13, 210009, Vitebsk, Belarus.
⁴ Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko 24, LT-03225, Vilnius, Lithuania. aivaras.kareiva@chf.vu.lt.
⁵ Department of Materials and Ceramics Engineering and CICECO - Aveiro Institute of Materials, University of Aveiro, 3810-193, Aveiro, Portugal. salak@ua.pt.

Abstract

Single-phase magnesium-aluminium layered double hydroxide (LDH) intercalated with dihydrogen phosphate was successfully produced by hydration of nanopowder of the respective mixed metal oxide (MMO) obtained using sol-gel based method followed by a two-step anion exchange hydroxide-to-chloride and chloride-to-phosphate. The MMO with the metal cation ratio of Mg/Al = 2:1 was prepared using the aqueous sol-gel method. Processes of the parent Mg₂Al-OH LDH formation and the successive anion-exchanges, ОН^- → Cl^- and Cl^- → H₂PO₄^-, were considerably accelerated via the application of high-power (1.5 kW) ultrasound. The crystalline phases formed at all stages of the Mg₂Al-H₂PO₄ LDH production were characterized using X-ray diffraction, scanning electron microscopy, scanning transmission electron microscopy, inductive coupled plasma optical emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Based on the data of chemical analysis and the XRD data, the type of the intercalated phosphate anion was determined and the arrangement of this anion in the interlayer was modelled.