Synthesis, magnetization, and photocatalytic activity of LaFeO_3 and LaFe_(0.9)Mn_(0.1)O_(3-δ)

摘要

LaFe_(0.9)Mn_(0.1)O_(3-δ) and LaFeO _3 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 Fe57 M?ssbauer 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 LaFeO_3, i.e., LaFe _(0.9)Mn_(0.1)O_(3-δ) were much higher than those of LaFeO_3 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 LaFeO_3 due to the existence of Mn 3+/Fe3+and Mn3+/Mn4+double exchange interaction in LaFe_(0.9)Mn_(0.1)O_(3-δ). The LaFe_(0.9)Mn_(0.1)O_(3-δ) 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.