Study on photocatalytic degradation of methylene blue by H4SiW12O40/TiO2/beads
H4SiW12O40/TiO2/beads光催化降解亚甲基蓝的研究

The floating TiO2/beads photocatalyst carrier was made by sol-gel technique with tetrabutyl titanate and hollow microbeads. Then, the composite H4SiW12O40/TiO2/beads photocatalyst was obtained by coating technique and characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and UV Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of decomposing methylene blue (MB) was studied. The influences of several operation parameters, such as light intensity, pH, aeration rate, pollutant concentration, and the quantity of catalyst, on the degradation of MB were studied. Under the neutrality or alkalescence conditions, 7.5 mg/L MB was treated with 0.25 g/L H4SiW12O40/TiO2/beads. After decomposed under 250 W ultraviolet light and 600 W visible light for 60 minutes, the decoloration rate of MB achieved 94.5% and 55%, respectively.