Structure and catalytic activity of magnetic composite photocatalyst SrFe₁₂O₁₉/SrTiO₃

Abstract

SrFe₁₂O₁₉/SrTiO₃ photocatalyst was synthesized with solgel method. The as-prepared composite catalyst was characterized by XRD, IR, SEM, BET, UV–vis and VSM. It was revealed that the specific surface area of SrFe₁₂O₁₉/SrTiO₃ was larger than that of pure SrTiO₃. The maximum absorption wavelength (λ_max) of the composite was 550 nm, which located in visible light region. The saturation magnetizations (M_s), remanent magnetization (M_r) and coercivity (H_c) of the magnetic composite were 19.8emu/g, 10.5emu/g and 2500G, respectively. The activity of the catalysts was evaluated by photodegradation of methylene blue (MB), and the degradation ratio with 25% SrFe₁₂O₁₉/SrTiO₃ was 98.6% at 2 h under the visible light illumination, while the degradation ratio with pure SrTiO₃ was 30% at the same condition. The results indicated that 25% SrFe₁₂O₁₉/SrTiO₃ held excellent photocatalytic activity as well as strong magnetization, which was beneficial to separate and recover completely. The recycling test confirmed that the magnetic composite catalyst was capable of using repeatedly, and the photocatalytic activity was above 80% after 5 cycles.

Keywords:

• SrFe₁₂O₁₉/SrTiO₃
• Photocatalytic activity
• Structural identification
• Strontium titanate
• Strontium ferrite
• Magnetic property

Acknowledgements

The authors also would like to thank the Scientific Research Foundation of State Key Lab of Coal Mine Disaster Dynamics and Control, PR China (No.2011DA105287-MS201206) and Chinese Scholarship Council (No.201506055005).