Preparation of SrTi0.1Fe0.9O3-δ and its photocatalysis activity for degradation of methyl orange in water

Magnetic perovskite-type SrTi0.1Fe0.9O3-delta was synthesized by stearic acid gel combustion method. The obtained powders were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), vibrating sample magnetometer (VSM) and UV-Visible absorption spectrum techniques. Mean valence of Fe ion and the concentration of oxygen vacancies in SrTi0.1Fe0.9O3-delta were measured by iodometric method. The magnetic properties of the SrTi0.1Fe0.9O3-delta were measured, and the SrTi0.1Fe0.9O3-delta was also evaluated for its photocatalytic activity towards the degradation of methyl orange (MO) under the sunlight irradiation. The experimental results show that the SrTi0.1Fe0.9O3-delta is the photocatalyst possessing of magnetic property and visible-light activity, i.e., bifunctional photocatalyst. The SrTi0.1Fe0.9O3-delta is applicable to the magnetic separation process and also shows excellent photocatalytic activity for the degradation of MO. The optimal conditions for photocatalytic degradation were methyl orange concentration of 20 mg L-1 at pH 6.0 with the SrTi0.1Fe0.9O3-delta concentration of 7.29 mg L-1 for 3 h. In addition, the SrTi0.1Fe0.9O3 is reusable and maintain relatively high activity. This study could point out a potential way to develop new and more active magnetic perovskite-type photocatalysts. (C) 2011 Elsevier B.V. All rights reserved.