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采用溶胶–凝胶法,以价廉的硫酸钛和硝酸铁为原料制备了不同含量的掺铁介孔二氧化钛。采用X射线衍射、扫描电子显微镜、热重–差示扫描量热分析、N2吸附–脱附、X射线光电子能谱、紫外–可见漫反射对样品进行表征。以亚甲基蓝(MB)为目标降解物,对催化剂的光催化性能进行了研究。结果表明:铁以Fe3+、Fe2+取代Ti4+进入TiO2的晶格。适量掺铁使TiO2的吸收带边发生红移,有利于提高样品光催化性能和保持良好的重复套用活性。最佳掺铁量(摩尔比)为n(Fe)/n(Ti)=2%,对应样品颗粒大小为0.1～0.2μm,比表面积为117.6 m2/g,孔容积为0.434 cm3/g,平均孔径为13 nm。重复套用4次后,240 min内对MB的总脱色率仍然达89.0%,降解率达70.7%。
Adopting sol - gel method, different content of iron - doped mesoporous titania was prepared by using cheap titanium sulfate and ferric nitrate as raw materials. The samples were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry-differential scanning calorimetry, N2 adsorption-desorption, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance. The photocatalytic activity of the catalyst was studied with methylene blue (MB) as the target degradation product. The results show that iron replaces Ti4 + into the crystal lattice of TiO2 with Fe3 + and Fe2 +. Appropriate amount of iron to red shift the edge of the absorption band of TiO2 is conducive to improving the photocatalytic properties of the sample and maintain a good activity of repeated application. The best iron content (molar ratio) is n (Fe) / n (Ti) = 2%, the corresponding sample particle size is 0.1 ~ 0.2μm, the specific surface area is 117.6m2 / g, the pore volume is 0.434cm3 / g, The aperture is 13 nm. After repeated application for 4 times, the total decolorization rate of MB still reached 89.0% within 240 min, the degradation rate reached 70.7%.