Photocatalytic activity of PbMoO4 molybdate synthesized by microwave method

Lead molybdate powders (PbMoO4) with scheelite-type structure were successfully synthesized at low temperatures by using microwave irradiation (MW) in ethylene glycol medium. The resulting powders were characterized by X-ray powder diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and adsorption-desorption N-2 isotherms (BET). PbMoO4 was tested as photocatalyst under UV irradiation for the degradation reaction of rhodamine B (rhB), indigo carmine (IC), orange G (OG), and methyl orange (MO). The bleaching of the organic dye solutions over PbMoO4 photocatalyst was quickly reached for rhB, IC, and OG with half-life times (t(1/2)) shorter than 7 min. On the other hand, MO shows a recalcitrant behavior to photocatalytic degradation with t(1/2)=172 min. Total organic carbon (TOC) analysis of samples irradiated revealed that mineralization of organic dyes by the action of PbMoO4 is feasible in 67% (rhB), 83% (IC), 55% (OG), and 60% (MO) after 96 h of UV irradiation. (C) 2013 Elsevier B.V. All rights reserved.