Photocatalytic degradation of methylene blue over Bi2WO6 under visible light irradiation

The Bi2WO6 photocatalysts were prepared by simple hydrothermal process. The photocatalytic activity of Bi2WO6 was evaluated by methylene blue (MB) under visible light irradiation (lambda > 400 nm). The MB degradation was examined to assess the influences of MB adsorption, pH value, MB initial concentration and the dosage of catalyst. The results demonstrated that in MB/ Bi2WO6 system, MB had been effectively degraded to about 76% within 4 h; and the degradation of MB over Bi2WO6 followed the first-order reaction kinetic model. Under the investigated conditions, the optimal parameters were obtained: the dosage of catalyst was 0.2 g/L, the initial concentration of MB 10 mg /L and pH value 9.30.