Magnetically recyclable Fe3+/TiO2@Fe3O4 nanocomposites towards degradation of direct blue 71 under visible-light irradiation

Fe3+/TiO2@Fe3O4 magnetic nanocompsites with 0.1–1 at% of Fe3+ content were synthesised by sol–gel method. The surface morphology, structure and crystalline phase of the nanocomposite were characterised by using XRD, SEM, HRTEM, EDX, BET, Diffuse reflectance spectroscopy (DRS) and VSM techniques. Photocatalytic activity experiments confirmed that as-prepared nanocomposite had good photodegradating behaviour to Direct Blue 71 under visible-light irradiation. 99.6% decomposition of dye was achieved within 50 min in the presence of the prepared photocatalyst. The nanocomposite could be easily recovered from the reaction solution by using a permanent magnetic bar and its photocatalytic activity remained 90% after five cycles of repetitious reusing. Then 0.5% Fe3+/TiO2@Fe3O4 nanocomposite can be used as highly efficient reusable catalysts.