Synthesis and characterization of γ-Bi2MoO6 prepared by co-precipitation: Photoassisted degradation of organic dyes under vis-irradiation

gamma-Bi2MoO6 was prepared by the co-precipitation method at 450 degrees C. The molybdate was characterized by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), simultaneous thermogravimetric and differential thermal analysis (TGA/DTA), diffuse reflectance spectroscopy (DRS), and surface analysis (BET). The synthesized material was tested as photocatalyst for the degradation of rhodamine B (rhB), indigo carmine (IC), and methyl orange (MO) under visible light irradiation. The gamma-Bi2MoO6 photocatalyst showed the capacity to bleach the dye solution in the following sequence: indigo carmine (IC)> rhodamine B (rhB)> methyl orange (MO). The degradation of rhB by gamma-Bi2MoO6 seems to happen predominantly through the photosensitization of the organic dye by the action of visible light irradiation. On the other hand, the IC degradation simultaneously happens by photosensitization and true photocatalytic processes. The activity of gamma-Bi2MoO6 for the degradation of MO was negligible. The reached mineralization degrees after 100 h of irradiation were 86% for rhB and 80% for IC. (c) 2010 Elsevier B.V. All rights reserved.