Hexacyanoferrate-interlayered hydrotalcite

Co—Fe Prussian Blue Analogue Intercalated into Diamagnetic Mg—Al Layered Double Hydroxides

“…The absorption peak at 1,380 cm -1 was observed in LDH-NO 3 , which is attributable to the symmetric vibration of the interlayer nitrate anion (Figure 1Ba). [28][29][30][31]36] LDH-Fe(CN) 6 showed that an absorption peak at 1,380 cm [25,37,38] SEM images of the LDH-NO 3 and LDH-Fe(CN) 6 are shown in Figure 1C. As can be seen, the rosette aggregation for LDH-NO 3 was observed (Figure 1Ca).…”

Intercalation of iron hexacyano complexes in Zn,Al hydrotalcite. Part 2. A mid-infrared and Raman spectroscopic study

“…Sample HTFE2 was prepared by direct synthesis from Zn and Al nitrate solutions (Zn/Al molar ratio=2.0) in decarbonated water and degassed with nitrogen for 20 min. A solution of K 4 [Fe(CN) 6 ] was added (Al/Fe molar ratio=2.0) with vigorous stirring at pH=10.2 and 60ºC. This pH produces the co presence of carbonate in the interlayer but a lower value yields to precipitation of K 2 Zn 3 [Fe(CN) 6 ] 2. .…”

“…A portion of 1.5 g of the solid was suspended in 100 ml of decarbonated water and then NaOH was added until a pH of 10.2 was reached. Next, the amount of K 4 [Fe(CN) 6 ] required for a Al/Fe ratio close to 1 was dissolved in 100 ml o decarbonated water and drop-wise added to the ZNALTA slurry with strong stirring and maintaining the pH at 10.2. After ageing for 24 h, the solid was filtered and washed, and dried at 60 ºC for 24 h, leading to sample TAFE2 (c=32.825 Å, a=3.072 Å).…”

“…One of these families corresponds to layered double hydroxides (LDHs), also known as hydrotalcite-like or hydrotalcitetype compounds, following hydrotalcite, a natural mineral with the composition [Mg 6 Al 2 (OH) 16 ]CO 3 ·4H 2 O. Partial isomorphous Mg 2+ /Al 3+ substitution gives rise to a net positive charge in the brucite-like layers, balanced by interlayer anions (carbonate in the case of hydrotalcite).…”

“…In the particular case of hydrotalcites containing iron, it has been reported [2] that the properties of the final oxides depend on the original location of the iron cations, i. e., in the brucite-like layers, or as part of a complex anion in the interlayer. The ironcontaining anions most widely used to intercalate in hydrotalcites are hexacyanoferrates [1][2][3][4][5][6][7][8][9][10][11][12] and many efforts have been made to explain the precise nature of the interlayer hexacyanoferrate species, as oxidation/reduction processes from Fe(II) to Fe(III) and viceversa have been reported [6,12]. In the present paper we report a detailed mid-infrared and Raman study of Zn,Al hydrotalcites containing intercalated hexacyanoferrate (II) and (III), in order to gain insight in the processes taking place in the interlayer.…”