Study On Synthesis And Photocatalytic Properties Of Double Perovskites A₂BMoO₆(A=Sr²⁺, Ba²⁺; B=Fe³⁺, Ca²⁺, Zn²⁺)

Double perovskite,which is similar to single perovskite, has unique physical and chemical properties, can be used as dielectric materials, luminescence materials, photocatalyst and magnetic materials.The peculiar structure and flexible form make this kind of material has good application prospect.Double perovskite-type oxides A2BMoO6(A=Sr²⁺, Ba²⁺; B=Fe3+, Ca²⁺, Zn²⁺) and perovskite-type oxides ABO₃(A=Sr²⁺, La3+; B=Fe3+, Al3+) were synthesized by Sol-Gel method using citric acid as the complexing agent. The different reaction conditions such as the sample pretreatment temperature, sintering temperature, pH, and dosage of reductant were explored by methods such as IR and TG. The samples were detected by means of X-ray powder diffraction?XRD? and scanning electron microscopy?SEM? in order to characterize the structure and the surface morphology. The results prove that perovskite complex oxides with single-phase structure can be synthesized by Sol-Gel method. The average particle size of prepared samples is 20⁴0 nm. So the samples belong to nanomaterials.This paper focused on photocatalytic activity of double perovskite-type to Azo dyes acid red 3B. And the illumination time, catalyst species, the dosage of catalyst, and the amount of H2O2 were also explored in this article.In the meanwhile, the effects of A and B ion on the photocatalytic activity of double perovskite-type oxides were studied. The results show that A-site cation is the inert component, it stabilizes the structure of catalyst, different A-site cation can cause the change of lattice parameters. B-site cation is the catalyst active component, its variation will change the semiconductor materials' band-gap energy. The band-gap energy of Sr2FeMoO6, Sr2ZnMoO6 and Sr2CaMoO6 is 1.94 eV, 2.74 eV and 2.82 eV respectively, which analyzed by UV-Vis DRS. And from this we also know that all the absorption peak wavelengths locate in the visible region of 400⁷00 nm. So they have higher photocatalytic activity under visible light irradiation. In addition, the photocatalytic performance of double perovskite Sr2FeMoO6 and perovskite SrFeO₃ was compared. It is found that the photocatalytic activity of Sr2FeMoO6 is higher than that of SrFeO₃.