Easily Oxidizable Polysulfide Anion Occluded in the Interlayer Space of Mg/Al Layered Double Hydroxide

Magnesium–aluminum layered double hydroxide containing polysulfide anions was prepared by a hydrothermal reaction from magnesium and aluminum hydroxides. Thioacetamide was used as the sulfide source. The product exhibits light green color corresponding to the S2- and S3- ions and turns to colorless when the sample was stored in air for several days or heat treated in air at 120 °C. The color change showed that the occluded polysulfide anions were oxidized to sulfate anion by atmospheric oxygen.