A novel core-shell like composite In2O3@CaIn2O4 for efficient degradation of Methylene Blue by visible light

In the process of preparing a visible light photocatalyst CaIn2O4, a novel core shell like composite In2O3@CaIn2O4 was observed at intermediate calcination temperatures, during the solid-state reaction between ball milled powders of CaCO3 and In2O3. The composition, crystallinity and photo absorption of the coupled phases obtained in the temperature range 873-1323 K, were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-vis diffused reflectance spectroscopy. The coupled composite phases In2O3@CaIn2O4 showed superior visible light induced photocatalytic degradation of Methylene Blue (MB) compared to single phase CaIn2O4. Selective charge separation and efficient charge transport at the interface when illuminated are considered to be the possible reasons for the enhanced photocatalytic performance of this composite catalyst. (c) 2007 Elsevier B.V. All rights reserved.