The Medification Of Al-double Perovskite Catalyst For Photocatelytic Degradation Of Phenol

In this paper,La₂AlBO₆（B=Fe,Co,Ni）double perovskite composite oxide catalysts were prepared by sol-gel method and glucose is complexing agent.On this basis,the La₂AlNiO₆ was doped by Bi,Ce and Y element,respectively,to investigate their photocatalytic properties for phenol.At the same time,we studied the phenol photodegradation activity of Bi-doped catalyst(La_1.9Bi_0.1AlNiO₆)at different preparation temperature（t=60℃,70℃,80℃）in the process of gelation,and then select a temperature which is more suitable for preparation of double perovskite composite oxide catalysts.All the as-prepared samples were characterized by XRD,FT-IR,SEM,BET,UV-Vis DRS,H2-TPR and magnetic test.The results are as follows:（1）XRD results show that La₂AlBO₆（B=Fe,Co,Ni）catalysts prepared by the sol-gel method（glucose is complexing agent）and calcination at 700 ℃ for 3h were all formed pure double perovskite composite oxide,i.e.La₂AlFeO₆,La₂AlCoO₆,La₂AlNiO₆.The degradation rate of phenol for the La₂AlFeO₆,La₂AlCoO₆,La₂AlNiO₆ catalysts are 42.11%,51.31%,and 57.61%,relatively.（2）On this basis,the La₂AlNiO₆ was doped by Bi,Ce and Y element,respectively,to prepare La_2-xC_xAlNiO₆（x=0.1,C=Bi,Ce,Y）double perovskite composite oxide.The results show that the degradation rate of phenol are 84.60%,71.31%and 62.20%,relatively,for La_1.9Bi_0.1AlNiO₆,La_1.9Ce_0.1AlNiO₆ and La_1.9Y_0.1AlNiO₆.It was concluded that a small amount of A-site doped in double perovskite-type composite oxide catalysts La₂AlNiO₆ with different metal elements（A=Ce,Bi,Y）have influence on its photocatalytic activity,and we found that doping with Ce,Bi,Y elements could improve the photocatalytic activity of the La₂AlNiO₆ sample,and Bi-doped La₂AlNiO₆(i.e.La_1.9Bi_0.1AlNiO₆)have optimal activity of degradation of phenol（84.60%）.（3）For the easier industrial production,temperature is an important factor.La_1.9Bi_0.1AlNiO₆ was prepared at different gel stirring temperature（t = 60℃,70 ℃,80℃）.The gelation time was 10h,8h and 6h at different temperature,respectively.It is found that though the phenol degradation rate of La_1.9Bi_0.1AlNiO₆ catalyst stirred at 80 ℃ is 79.41%,the gel formation rate of sample is the fastest,so 80 ℃ is more suitable for industrial production.