光催化剂Sm_2FeSbO_7的制备及光物理和光催化性能表征（英文）

Preparation, Photophysical and Photocatalytic Property Characterization of Sm_2FeSbO_7 during Visible Light Irradiation

首次采用固相反应法制备了新型光催化剂Sm_2FeSbO_7,有效地降解了水中有机污染物。利用X射线衍射、扫描电镜、X射线光电子能谱、傅里叶变换红外光谱、透射电子显微镜和紫外-可见光谱仪对Sm_2FeSbO_7的结构和光催化性能进行了表征。Sm_2FeSbO_7为烧绿石型结构,立方晶系和空间群Fd3m结晶。Sm_2FeSbO_7的晶格参数a为1.035 434 nm。Sm_2FeSbO_7的带隙经估算为2.46 eV。用Sm_2FeSbO_7作为光催化剂在可见光照射下降解靛蓝胭脂红,并与氮掺杂Ti O_2对比。结果表明,与掺氮TiO_2相比,Sm_2FeSbO_7在可见光照射下光催化降解靛蓝胭脂红显示出较高的光催化活性。总有机碳的减少,无机产物的逐渐形成,SO_4^(2-)和NO_3^-以及CO_2的演变揭示了在光催化过程中靛蓝胭脂红的连续矿化。检测了一些来自光催化降解靛蓝胭脂红的中间体,如邻硝基苯甲酸和邻硝基苯甲醛,并获得了可能的靛蓝胭脂红光催化降解路径。

In order to efficiently degrade organic pollutants in water,a new photocatalyst Sm2FeSbO7 was prepared by a solid-state reaction method for the first time.The construction and photocatalytic property of Sm2FeSbO7 had been characterized by X-ray diffraction,scanning electron microscopy,X-ray photoelectron spectroscopy,Fourier-transform infrared spectroscopy,transmission electron microscope and UV-visible spectrometer.Sm2FeSbO7 crystallized with a pyrochlore-type structure,a cubic crystal system and a space group Fd3m.The lattice parameter a of Sm2FeSbO7 was 1.035 434 nm.The band gap of Sm2FeSbO7 was estimated to be 2.46 eV.The photocatalytic degradation of indigo carmine was accomplished under visible light irradiation with Sm2FeSbO7 as a catalyst compared with nitrogen-doped TiO2.The results indicated that Sm2FeSbO7 displayed higher photocatalytic activity compared with nitrogen-doped TiO2 for the photocatalytic degradation of indigo carmine under visible light irradiation.The reduction of the total organic carbon,the gradual formation of inorganic products,SO42-and NO3-,and the evolution of CO2 revealed the continuous mineralization of indigo carmine during the photocatalytic process.Some intermediate products which came from the photocatalytic degradation of indigo carmine were detected,such as o-nitrobenzoic acid and o-nitrobenzaldehyde,and a possible photocatalytic degradation path of indigo carmine was acquired.