Synthesis, magnetization, and photocatalytic activity of LaFeO3 and LaFe0.9Mn0.1O3-δ

LaFe0.9Mn0.1O3-delta and LaFeO3 were synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared, XPS techniques, UV-Visible absorption spectra techniques, vibrating sample magnetometer, and room temperature Fe-57 Mossbauer spectra. They were also evaluated for their photocatalytic activity toward the degradation of methyl orange under the sunlight irradiation. The experimental results show that the catalytic activities of the Mn-doped in LaFeO3, i.e., LaFe0.9Mn0.1O3-delta were much higher than those of LaFeO3 due to its higher oxygen vacancies, variable valency Mn ions and the strong absorption in visible light, and it has higher magnetic property than that of LaFeO3 due to the existence of Mn3+/Fe3+ and Mn3+/Mn4+ double exchange interaction in LaFe0.9Mn0.1O3-delta. The LaFe0.9Mn0.1O3-delta is the photocatalyst with intrinsic magnetic property and visible light activity, and it is applicable to the magnetic separation process for its higher saturated magnetization (M-s), lower coercivity (H-c), and remanent magnetization (M-r) as well as the superparamagnetic contribution in the sample, and it can be reusable and maintain relatively high activity.