Synthesis and investigation of photoactive sillenite bi24ga2o39 and brownmillerite ba2in2o5 for energy and environmental applications

Abstract

Water and air pollution are some of the major issues demanding our newlineattention towards remediation of environment. Numerous materials have newlinealready been explored for photocatalytic treatment of contaminated water as newlinewell as H2 generation. Role of sulfide, halides, carbon-based materials and newlinemetal alloys/ions are more pronounced in the photocatalytic based newlineapplications, but their efficiency is marred by features such as wide band gap, newlinelow stability, safety measures, rare availability and expensive. On the other newlinehand, oxides offer advantages such as higher stability in atmosphere, ease to newlinehandle/storage and economical affordability. The present work intensively newlineexplores oxide based visible light driven photoactive materials for the energy newlineand environmental remediation. We present our work on oxide-based newlinephotocatalysts, sillenite and brownmillerite structured materials for newlinephotocatalytic applications. The non-stoichiometric form of sillenite newlinesynthesized here is that of Bi24M2O39. Bi present in the structure has newlineelectrostatically active 6s newline2 lone electron pairs which induces polarization to newlineavert the recombination of photo generated electron hole pairs significantly newlinepromoting higher photocatalytic behavior. With this beneficial nature, newlinesillenite materials are one of the preferred materials to degrade persistent newlineaqueous pollutants. In the interim, brownmillerite materials are derived from newlinethe perovskite structure. They possess one-sixth ordered oxygen vacancies in newlinealternating layers along the [110] direction of cubic perovskite. Such specific newlineoxygen deficient structures lead to enhanced adsorption sites and sometimes newlineact as trap sites, preventing recombination and improving the photocatalytic newlineactivity. In addition, these materials have narrow band gaps and wide newlineabsorption in the visible region of solar spectrum newline