Sr~(2+)掺杂及非化学计量LaFeO_3的溶剂热制备及光催化性能

利用简单的溶剂热法制备LaFeO_3、La_(0.8)Sr_(0.2)FeO_(3-δ)以及非化学计量的La_(0.8)Sr_(0.2)FeO_(3-δ)(x=0.97,1.03)纳米颗粒。采用XRD、TEM、UV-Vis、XPS等手段对样品的形貌和结构进行表征,以孔雀石绿(MG)光降解为模型反应,在最大吸收波长下(616.9nm)考察材料的光催化性能。结果表明:Sr~(2+)的掺入减小了晶粒尺寸,致使晶体产生晶格畸变并形成氧空位V··O,抑制电子-空穴重组,增大量子效率;掺入Sr~(2+)并改变非化学计量,使得催化剂在可见光区域有较强的光吸收,比表面积增大,其中(La_(0.8)Sr_(0.2))1.03FeO_(3-δ)的比表面积最大(20.164 4m2/g),可见光降解效率也最高(83.8%)。Sr~(2+)掺杂及非化学计量LaFeO_3的可见光催化活性均高于纯LaFeO_3。

Solvothermal of Sr2+ doped and nonstoichiometric LaFeO3 and their photocatalytic activity

LaFeO3 ,La0.8 Sr0.2 FeO3-δand nonstoichiometric (La0.8 Sr0.2 )xFeO3-δ(x =0.97,1.03)nanoparticles were fabricated via a simple solvothermal method.The morphologies and structures of the samples were character-ized by XRD,TEM,UV-Vis,XPS and so on.Malachite green (MG)photodegradation was used as a model reac-tion to investigate the photocatalytic activity of these samples under the maximum absorption wavelength (6 1 6.9 nm).The results indicate that the doping of Sr2+ reduce the grain size and cause lattice defects and oxygen vacanciesV··O to be formed,which are in favor of hindering the recombination of electrons and holes,increasing the quantum efficiency.Doping Sr2+ and changing nonstoichiometry make the catalysts have strong absorption in visible region and large specific surface area. The specific surface area of (La0.8 Sr0.2 )1.03 FeO3-δ is the largest (20.164 4 m2/g)and the visible degradation efficiency of (La0.8 Sr0.2 )1.03 FeO3-δis the highest(83.8%)among the catalysts.The photocatalytic activities of doped Sr2+ and nonstoichiometric LaFeO3 are higher than those of pure LaFeO3 .