Nd掺杂LaFeO_3纳米粉体的合成及其可见光催化活性

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.

Preparation and Visible-Light Photocatalytic Activity of Nd-Doped LaFeO3 Nanopowders

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 Nd0.1FeO3 served 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.