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采用溶胶-凝胶法制备铁、碘单掺杂及共掺杂的纳米晶TiO_2光催化剂,用X射线衍射(XRD)、X射线光电子能谱(XPS)和紫外可见(UV-vis)漫反射光谱对其进行表征,研究了其降解亚甲基蓝的光催化性能。结果表明,催化剂样品为锐钛矿相,平均粒径为7-15 nm.掺杂使样品的光吸收性能显著改善。掺杂I引起样品的晶粒尺寸减小和光吸收范围的拓展,导致其光催化活性显著提高;对于共掺杂样品,随着Fe掺杂量的增加,其光催化活性呈现先增加后减小的变化趋势,掺杂量为0.2%的光催化性能最好.根据Fe引入后样品晶粒尺寸、光吸收性能及能带结构等因素的变化,对其光催化性能变化的机制进行了讨论.
The nanocrystalline TiO_2 photocatalysts doped with iron and iodine were prepared by sol-gel method. The photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance Spectra were used to characterize its photocatalytic degradation of methylene blue. The results show that the catalyst samples are anatase phase and the average particle size is 7-15 nm. The doping improves the light absorption properties of the samples significantly. The doping of I led to the decrease of the grain size and the expansion of the light absorption range of the sample, resulting in a significant increase in the photocatalytic activity. For the co-doped sample, the photocatalytic activity of the sample increases first and then decreases with the increase of Fe doping The best photocatalytic activity is 0.2% doping.According to the changes of the grain size, optical absorption and energy band structure of the sample after the introduction of Fe, the mechanism of the photocatalytic performance change is discussed.