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将硅藻土分散在硝酸铋溶液中,经冷冻干燥后于空气中煅烧得到了Bi2O3/硅藻土质量比为0.10:1.00～0.60:1.00的一系列复合光催化剂。用X射线粉末衍射、场发射扫描电子显微镜、比表面积及孔径分析仪对所制备的产物进行了结构表征。以500W氙灯为光源,亚甲基蓝为模拟污水中有机染料,评价了复合光催化剂的可见光催化性能。结果表明:晶粒尺寸约31.7nm的Bi2O3较好地分散在硅藻土表面,既保留了硅藻土自身的多孔结构,又发挥了Bi2O3的可见光催化性能。负载Bi2O3的复合光催化剂能吸收波长小于520nm的可见光和紫外光,Bi2O3/硅藻土质量比为0.40:1.00时,氙灯光照2h能将20mg/L的亚甲基蓝溶液降解90%以上。
Diatomaceous earth was dispersed in bismuth nitrate solution and calcined in air after freeze-drying to obtain a series of composite photocatalysts with a mass ratio of Bi2O3 to diatomite of 0.10: 1.00-0.60: 1.00. The prepared product was characterized by X-ray powder diffraction, field emission scanning electron microscopy, specific surface area and pore size analyzer. Using 500W xenon lamp as the light source and methylene blue as the organic dye in the simulated wastewater, the photocatalytic performance of the composite photocatalyst was evaluated. The results show that Bi2O3 with a grain size of about 31.7nm is well dispersed on the surface of diatomaceous earth, which not only retains the porous structure of diatomite itself, but also displays the visible light catalytic activity of Bi2O3. Bi2O3 supported composite photocatalyst can absorb visible light and ultraviolet light with wavelength less than 520nm, Bi2O3 / diatomite mass ratio of 0.40: 1.00, xenon lamp light 2h 20mg / L methylene blue solution can be degraded more than 90%.