Sr^(2+)掺杂及非化学计量LaFeO_3的溶剂热制备及光催化性能

Solvothermal of Sr^(2+) doped and nonstoichiometric LaFeO_3 and their photocatalytic activity

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。

LaFeO3,La0.8Sr0.2FeO3-δand nonstoichiometricLa0.8Sr0.2FeO3-δ（x =0.97,1.03）nanoparticles were fabricated via a simple solvothermal method.The morphologies and structures of the samples were characterized by XRD,TEM,UV-Vis,XPS and so on.Malachite green（MG）photodegradation was used as a model reaction to investigate the photocatalytic activity of these samples under the maximum absorption wavelength（616.9nm）.The results indicate that the doping of Sr2＋ reduce the grain size and cause lattice defects and oxygen vacancies V··Oto 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（La0.8Sr0.2）1.03FeO3-δ is the largest（20.164 4m2/g）and the visible degradation efficiency of（La0.8Sr0.2）1.03FeO3-δ is the highest（83.8%）among the catalysts.The photocatalytic activities of doped Sr2＋ and nonstoichiometric LaFeO3 are higher than those of pure LaFeO3.