Synthesis and photocatalytic properties of lanthanum doped anatase TiO 2 coated Fe 3 O 4 composites

A composite photocatalyst (La/TiO 2 /Fe 3 O 4 ) with a lanthanum doped TiO 2 (La/TiO 2 ) shell and a magnetite core was prepared by coating photoactive La/TiO 2 onto a magnetic Fe 3 O 4 core. The morphological, structural, and optical properties of as‐prepared samples were characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD) and UV‐vis absorption spectroscopy. The effect of lanthanum content on the photocatalytic properties was studied, and the result revealed that 0.15 mol% La/TiO 2 /Fe 3 O 4 exhibited the highest photoactivity. The photocatalytic properties of the prepared photocatalyst under UV and visible light were investigated in aqueous solution using methyl orange (MO) as a target pollutant. The results showed that the prepared photocatalyst was activated by visible light and used as an effective catalyst in photooxidation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, La/TiO 2 was tightly bound to Fe 3 O 4 and could be easily recovered from the medium by a simple magnetic process.