| At present,photocatalytic degradation of dye wastewater has attracted much attention,and finding excellent photocatalysts has become a hot topic.The compounds with double perovskite structure are potential optical,electromagnetically and photocatalytic materials for their unique structural features.In this paper,La2FeBO6（B=Ti,Cr,Mn）,La FeO3 and A-doped La2-xSrxFeTiO6were synthesized by citric acid sol-gel method.TG-DSC,IR,XRD,SEM and UV-Vis DRS were used to characterize the prepared products.The effects of the amount of complex,the pH of the system,the use of the dispersant,the heat treatment conditions and the sintering temperature of the photocatalysts were investigated.The results show that La2FeCrO6 can be synthesized when n柠:n金=1:1,pH=3,drying at 120℃for 12 h,preheating at 600℃for 3 h and sintering at 900℃for 3 h.In this paper,the photocatalytic activities of the iron series double perovskite photocatalysts were studied by degrading the methylene blue dye solution.The effects of different catalysts,initial concentration of dye,the amount of catalyst,the pH of solution and the amount of H2O2 were investigated,the results show that the degradation rate of dye is higher when the concentration of dye is 8 mg/L,the amount of catalyst is 100 mg,pH=11,and 2.5 mL H2O2 is added.The decolorization rates of the methylene blue dye solution are 81.7%,85.8%and 75.7%when La2Fe BO6（B=Ti,Cr,Mn）are used as photocatalysts,respectively.The ions radius,d electron configuration,band gap of catalysts are different,their forbidden band width are 2.63eV,2.60 eV,2.65eV,there are absorption peaks in the visible range,indicating that the three catalysts can respond within the visible range.The photocatalytic activity of La2FeCrO6 and LaFeO3 were compared,the photocatalytic activity of the former is stronger than that of the latter.It is found that with the increase of Sr content,the band gap of La2Fe TiO6 is decreased and the photocatalytic activity is increasing. |
PDF Full Text Request