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

摘要

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, Moessbauer 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.