Nd掺杂LaFeO_3纳米粉体的合成及其可见光催化活性(英文)

Preparation and Visible-Light Photocatalytic Activity of Nd-Doped LaFeO_3 Nanopowders

采用柠檬酸络合法于600℃煅烧2h合成了钙钛矿型La1-xNdxFeO3(x=0,0.05,0.10,0.15,0.20,0.25)纳米光催化剂,并利用X射线能谱(EDS)、热重-差热(TG-DTA)、X射线衍射(XRD)、扫描电镜(SEM)以及紫外可见漫反射吸收光谱(UV-VisDRS)等技术进行了表征,以次甲基蓝为目标降解物、以荧光灯模拟可见光源考察了Nd掺杂量对其可见光催化活性的影响.结果表明,Nd已经掺入LaFeO3晶体中,Nd的最佳掺杂量为x=0.1.La0.9Nd0.1-FeO3光催化剂可将次甲基蓝1h降解率由未掺杂的56.0%提高到80.4%,这是由于掺杂后粉体粒径由20.2nm减小到16.9nm,表面原子比例增加以及掺杂后纳米粉体在可见光区的吸收增强所致.

Nano-photocatalysts of La1-xNdxFeO3（ x = 0,0. 05,0. 10,0. 15,0. 20,0. 25） with perovskite-type structure have been prepared by citric acid complex method at 600 °C for 2 h. The prepared pure and Nd-doped LaFeO3 powders were characterized by energy dispersive X-ray spectrometer （ EDS） , thermogravimetry-differential thermal analysis （ TG-DTA） ,X-ray diffraction （ XRD） ,scanning electron microscope （ SEM） and ultraviolet-visible diffuse reflection spectra （ UV-Vis DRS） . The visible-light photocatalytic activity of the photocatalysts was tested with methylene blue as an objective decomposition substance using fluorescence light as a visible light resource. The results show that Nd element is doped into the lattice of La element in LaFeO3. The optimum doping concentration of Nd is 0. 1 and the degradation rate of methylene blue is improved from 56. 0% to 80. 4% for 1 h photoirradiation when La0.9 Nd0.1 FeO3served as the photocatalyst instead of LaFeO3. The reasons are that the particle size decreases from 20. 2 nm to 16. 9 nm,leading to more surface atoms on La0.9 Nd0.1FeO3 powders and that visible-light absorption capacity increases after doping.