LaFeO_3和Fe_2O_3制备及其对三硝基甲苯光催化降解作用研究

Preparation and Study of LaFeO_3 and α-Fe_2O_3 for 2,4,6-Trinitromethylbenzene Photocatalytic Degradation

采用硬脂酸溶液燃烧法直接合成了具有较高比表面积钙钛矿型LaFeO3和α-Fe2O3.通过X射线衍射、扫描电镜、傅里叶红外、紫外可见漫反射及光电子能谱等技术对其进行了表征。所合成的LaFeO3在紫外和可见光区有明显吸收。紫外和太阳光下以LaFeO3为催化剂,对2,4,6-三硝基甲苯(TNT)模拟废水进行了初步的光催化降解研究。实验结果表明:太阳光下0.5×10-3mol LaFeO3对TNT的光催化降解效果与紫外光下相当;1 h内降解率达51%,表现了较好的光催化活性;另外,紫外光下LaFeO3光催化效果明显优于α-Fe2O3,这与LaFeO3表面吸附了较多的吸附氧与羟基相关。

Perovskite-type oxide LaFeO3 and α-Fe2O3 with high specific surface areas were directly synthesized by stearic acid solution combustion method.The obtained powders were characterized by XRD,SEM,FT-IR,UV-Vis DRS and XPS techniques.Photocatalytic degradation of simulative wastewater of 2,4,6-trinitromethylbenzene（TNT） were preliminary studied using solar/UV illuminated LaFeO3.The experimented results show that 0.000 5 mol LaFeO3 under ultraviolet has the same photocatalytic activation as it does under solar; the degradation rate of TNT is 51% within 1 h;under ultraviolet,the catalytic activity of LaFeO3 is higher than that of α-Fe2O3 which is due to the high concentrations of surface-adsorbed oxygen and hydroxyl of LaFeO3.