Fe(CN)63−/Fe(CN)64− redox in the interlayer determined by the charge density of ZnnCr-layered double hydroxides

Redox of Fe(CN) and Fe(CN) in the ZnCr layered double hydroxide interlayer has been investigated. The conversion from Fe(CN) to Fe(CN) or from Fe(CN) to Fe(CN) in the ZnCr-LDH interlayer has been confirmed, depending on the Zn:Cr molar ratio. Both Fe(CN) and Fe(CN) are observed in all samples no matter whether the initial anion is Fe(CN) or Fe(CN) before precipitation. Deconvolution of the FTIR band around 2100 cm reveals that the relative amount of Fe(CN) and Fe(CN) in the LDH interlayer is considerably dependent on the Zn:Cr molar ratio. In brief, Fe(CN) is preferred at the ratio of 2:1 while there is more Fe(CN) in the ratio of 4:1. Therefore, it is our hypothesis that the charge density of the hydroxide layer is a key factor that directs the redox of Fe(CN) /Fe(CN) . The possible redox processes have also been proposed