Magnetization and photocatalytic activities of La0.8Sr0.2Mn1−xTixO3−δ (x=0–0.15)

Abstract

Perovskite-type La0.8Sr0.2Mn1−xTixO3−δ (x=0–0.15) were synthesized and characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Vibrating sample magnetometer (VSM) and UV–visible absorption spectrum techniques. The magnetic properties of the La0.8Sr0.2Mn1−xTixO3−δ (x=0–0.15) were measured, and the photocatalytic activities were evaluated by the degradation of methyl orange (MO) under the sunlight irradiation. Experimental results indicate that the La0.8Sr0.2MnO3−δ and La0.8Sr0.2Mn0.95Ti0.05O3−δ exhibit soft ferromagnetic behavior, and have much higher magnetizations and lower coercivities and remanences than the perovskite-type oxides reported in literatures. The La0.8Sr0.2MnO3−δ and La0.8Sr0.2Mn0.95Ti0.05O3−δ also exhibit high solar-light-driven photocatalytic activities for MO degradation. The photocatalytic activities of the La0.8Sr0.2Mn0.95Ti0.05O3−δ are higher than those of the La0.8Sr0.2MnO3−δ duo to its higher oxygen vacancies, the variable valences of Mn and Ti, and the stronger absorption in UV–visible region. In addition, the La0.8Sr0.2Mn0.95Ti0.05O3−δ is applicable to the magnetic separation process for its high magnetizations. Deactivated La0.8Sr0.2Mn0.95Ti0.05O3−δ photocatalyst can be recovered by washing with acetone, and can be reusable and maintain relatively high activities. Hence, it is anticipated that the La0.8Sr0.2Mn0.95Ti0.05O3−δ could be applied in wastewater treatment system under solar in the near future.