Synthesis and properties of novel Ba(II)Fe(III) layered double hydroxides

Double hydroxides of Ba(II) and Fe(III) were prepared by the co-precipitation method. Co-precipitation was facilitated by applying highly alkaline, carbonate free NaOH solutions with varying base concentrations (2-20 M). The substances, thus obtained, were characterised by thermal methods. XRD spectra of samples treated at various temperatures, Mossbauer and X-ray absorption spectroscopies. It was found that in extremely concentrated base solutions (>= 10 M) layered double hydroxides, most probably with intercalated OH ions, were formed, indeed, while at low base concentration the Fe(III) ions were precipitated as various oxyhydroxides and the Ba(II) ions remained dissolved. (C) 2009 Elsevier B.V. All rights reserved.