Ultrasound‐Induced Rapid Intercalation of Biselenite in Layered Double Hydroxides

Abstract

The deintercalation of carbonate (CO32–) ions from MgAl‐layered double hydroxides (LDHs) (Mg/Al = 2) both in monolayer films and powdered samples under atmospheric conditions in ethanol was investigated. A selenous acid precursor was incorporated into the interlayer gallery. Treatment with 0.5 M selenous acid (H2SeO3) for 30 min with powdered LDHs or with 0.1 M H2SeO3 for 5 min with the thin film LDHs resulted in carbonate ions being exchanged with biselenite (HSeO3–) ions. Electron microscopy showed that the morphologies of the original LDH particles remained after the reaction, despite the ultrasound being continuously applied for up to 2 h. XRD, FTIR and Raman spectroscopic scattering results strongly suggested that cyclic dimers of biselenite ions were incorporated into the gallery spaces of the LDHs, vertically arranged to the horizontal axes of the MgAl‐LDH layers.

Spectroscopic evidence for selenium(iv) dimerization in aqueous solution

“…In structure C, the symmetrical group is consequently reduced to C i and should have two types of vibrational modes, A g and A u , distributed into 24 fundamental vibrations as follows: Γ vib = 12A g + 12A u . This is in agreement with the recently proposed structure of cyclic dimers of HSeO 3 − ions intercalated in LDH phases 36 and present in solid NaHSeO 3. 37,38 These dimers (C i symmetry) are joined by hydrogen bonds around their centre of symmetry.…”

“…This is in agreement with the recently proposed structure of cyclic dimers of HSeO 3 − ions intercalated in LDH phases 36 and present in solid NaHSeO 3. 37,38 These dimers (C i symmetry) are joined by hydrogen bonds around their centre of symmetry.…”

Fluorescein dye intercalated layered double hydroxides for chemically stabilized photoluminescent indicators on inorganic surfaces

“…We note that the current reaction conditions could efficiently protect the incorporated carbonates from carbon dioxide. We also note that the intercalation of the fluorescein dyes could be effectively induced by the ethanol in the reaction media, 26,27 because the small amount of ethanol provided solubility for the de-protonation of the fluorescein dyes to the anionic form and for the fast diffusion of the fluorescein dye into the LDH interlayers without any structural damage to the LDH particles. The XRD pattern of the LDH-F film also shows the intense (00l) reflections, implying a highly oriented arrangement of intercalated fluorescein dyes in the LDH layers.…”

Réteges kettős hidroxidok előállítása ultrahang besugárzással segített mechanokémiai módszerrel

“…Végül akad példa arra is, amikor az interkalációs folyamatok alatt használtak ultrahangos kevertetést. Segítségével nagyobb mennyiségben tudták beépíteni a kívánt aniont [130], illetve az igen nehezen cserélhető karbonát aniont is jó hatékonysággal helyettesíteni tudták egy másik szervetlen anionnal [131,132]. 17. ábra Az alkalmazott ultrahangforrások és az ultrahangos közeg hőmérséklet-szabályozásának bemutatása.…”