H4SiW12O40/TiO2/beads光催化降解亚甲基蓝的研究

以钛酸四丁酯为原料,空心微珠为载体,采用溶胶-凝胶法制备TiO2/beads光催化剂载体,然后浸渍法制备出H4SiW12O40/TiO2/beads表面负载修饰型复合光催化剂,并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H4SiW12O40/TiO2/beads对亚甲基蓝降解的光催化活性,考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明,在中性条件下,H4SiW12O40/TiO2/beads催化剂的投加量为0.25 g/L,浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。

Study on photocatalytic degradation of methylene blue by H4SiW12O40/TiO2/beads

The floating TiO2/beads photocatalyst carrier was made by sol-gel technique with tetrabutyl titanate and hollow mierobeads. 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.