Hydrothermal Synthesis of Bismuth Vanadate-Alumina Assisted by Microwaves to Evaluate the Photocatalytic Activity in the Degradation of Methylene Blue

The present study synthesized powders of bismuth vanadate-alumina (BiVO4-Al2O3) by means of the microwave-assisted hydrothermal method. The powders prepared were characterized by X-ray diffraction, scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of the synthesized powders was determined via the oxidative degradation of methylene blue (MB) in aqueous solution under the irradiation of visible light. The effect of parameters such as alumina concentration, synthesis temperature and reaction time was examined in order to determine their influence on crystal size, morphology, photocatalytic activity and the type of crystal structure. The sample prepared under conditions of 160 degrees C, 60 min and 1.5 wt % Al2O3, presented the highest percentage of degradation and photonic efficient of all samples, which was close to 86% and 4.86 x 10(-6) respectively, under the parameters of the experimental design proposed for this research.