Nanoscale Synthesis and Photocatalytic Properties of Three Layered Aurivillius Compounds, Bi2A2TiM2O12 (A= Ca, Sr, Ba and M= Nb, Ta)

A group of three layered Aurivillius compounds with composition Bi2A2TiM2O12, where A=Ca, Sr, Ba and M = Nb and Ta, have been synthesized in nano scale through the complex polymerization method. The nano-scale powders show square shape plate-like crystallites with dimensions ~100×100×40 nm3. BET analysis confirms the expected average surface area ~10 m2/g. Surface area was found to depend on the firing temperature and dwell time as indicated through BET. The DLS analysis in an aqueous methanol solution indicates that particles are largely agglomerated. Measurements of the decomposition rate of methylene blue indicates that all compounds are photocatalytically active.