Unique properties of α-NaFeO2: De-intercalation of sodium via hydrolysis and the intercalation of guest molecules into the extract solution

• Facile de-intercalating Na from NaFeO2.
• Formation of layered sodium hydrogen carbonate hydrate.
• Intercalation chemistry on layered sodium hydrogen carbonate hydrate.

We report on a versatile method for the de-intercalation of Na from α-NaFeO2 by using water to produce α-Na1−xFeO2, where x ≈ 1. This de-intercalation technique provides an excellent route to ion exchange Na with other metal ions in α-NaFeO2. The hydrolysis mechanism is provided. We show that the extracted solution captures CO2 from the atmosphere leading to the formation of sodium hydrogen carbonate hydrate crystals. The lamellar structure of the hydrate crystals was confirmed by powder X-ray diffraction, and were found Na-deficient via elemental analysis. Intercalation of guest molecules such as polymers, alcohols, and inorganic ions into the gallery space of the newly formed sodium hydrogen carbonate hydrate crystals was demonstrated by the use of powder X-ray diffraction technique. The reported materials were also characterized by Mössbauer spectroscopy, thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy.

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