Study On Perovskite Type Photocatalytic Materials With Wide Spectral Response

In recent years,the environmental pollution is becoming more and more serious.As a new technology of environmental protection,photocatalysis technology has many advantages in the degradation of pollutants.Perovskite photocatalyst has become a hot topic in the field of photocatalysis technology due to its special crystal structure,thermal stability and chemical stability.In this paper,based on the good application prospect of perovskite photocatalyst,the modification of KSr2Nb3O10 and SrTiO₃ was studied.Furthermore,XRD,SEM,TEM,EDS,DRS and XPS was used to analyze the characterization of physicochemical properties of materials,and through the degradation of methyl orange to study the photocatalytic performance of catalyst.The main contents are as followings:1)The perovskite photocatalyst of KSr2Nb3O10 was synthesized by high temperature solid phase method.HSr₂Nb₃O₁₀ was obtained by exchange acid.The particles size and the light absorption capacity of HSr₂Nb₃O₁₀ were close to that of KSr2Nb3O10.However,part of the layered structure of HSr₂Nb₃O₁₀ was cracked and the photocatalytic activity of HSr₂Nb₃O₁₀ was remarkably improved.HSr₂Nb₃O₁₀/nC6H13NH2 was obtained by pillared hexylamine.The layer structure was exfoliated inot a sheet and the degradation rate of methyl orange reached 77.9% under the visible light after 60 min,the photocatalytic activity of HSr₂Nb₃O₁₀/nC6H13NH2 was far higher than that of KSr2Nb3O10 and HSr₂Nb₃O₁₀.In addition,the modification experiments of KSr2Nb3O10 doped with Cr,Er and La were studied followed with exchange acid and pillar.The experimental result showed that Cr doped HSr₂Nb₃O₁₀/nC6H13NH2 had the highest catalytic activity.2)The perovskite photocatalyst of SrTiO₃ was synthesized by high temperature solid phase method and further combined with La doped WO₃ to form composites by hydrothermal method.The best photocatalytic activity of La-WO₃/SrTiO₃ composites was discussed by adjusting the molar proportion of SrTiO₃ and La-WO₃.The experimental results showed that SrTiO₃ and La-WO₃ bounded together tightly and heterogeneous structure was formed,the band gap was decreased and the visible light absorption ability was enhanced.Moewover,La-WO₃/SrTiO₃-50% composites had the best photocatalytic activity and the methyl orange completely degraded under visible light after 60 min.3)The perovskite photocatalyst of SrTiO₃ was synthesized by high temperature solid phase method and further combined with Bi2O₃ to form SrTiO₃/Bi2O₃ composites by hydrothermal method.The photocatalytic activity of SrTiO₃/Bi2O₃ with different molar ratio between SrTiO₃ and Bi2O₃ was studied.The experimental results showed that SrTiO₃ and Bi2O₃ bounded together tightly and heterogeneous structure was formed,the band gap was decreased and the visible light absorption ability was enhanced.Moewover,the photocatalytic activity of SrTiO₃/Bi2O₃ composites was better than that of pure Bi2O₃ and SrTiO₃,SrTiO₃/Bi2O₃-150% composites showed the best photocatalytic activity and the methyl orange completely degraded under visible light after 45 min.