Solar-based photoreduction of methyl orange using zeolite supported photocatalytic materials

A new class of novel photocatalysts has been prepared by supporting TiO2 on the zeolite matrix by various routes of synthesis. Different transition metals like cobalt, nickel, and ruthenium have been incorporated in these photocatalysts, alongwith molybdenum based heteropolyacid (HPA) to improve the photocatalytic activity of these materials. Photoreduction of methyl orange under solar radiation was compared with photoreduction in presence of artificial visible light illumination to evaluate their photocatalytic activity. The quantity of methyl orange photoreduced by the cobalt containing photocatalyst was about 2.40 mg/g of TiO2 under the influence of sunlight as compared to 4.111 mg/g of TiO2 under artificial visible light illumination. However, the efficiency of the photocatalyst is high as compared to P25 TiO2 under solar light (0.508 mg/g of TiO2). The high photocatalytic activity of these materials is due to the synergistic effect of incorporation of transition metals in combination with TiO2 and HPA supported by the zeolite matrix. These materials are being evaluated for photocatalytic water splitting. (c) 2006 Elsevier B.V. All rights reserved.