Preparation of Fe3O4/TiO2 magnetic photocatalyst for photocatalytic degradation of phenol

In this study, Fe₃O₄ magnetic nanoparticles were prepared from FeCl₂/FeCl₃ and NaOH solution by chemical co-precipitation method in an impinging stream-rotating packed bed. Then, Fe₃O₄/TiO₂ photocatalyst was prepared for photocatalytic degradation of phenol by sol–gel method using butyl titanate and Fe₃O₄ magnetic nanoparticles. The surface morphology, structure and crystalline phase of Fe₃O₄/TiO₂ were characterized by high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, dynamic light scattering and ultraviolet–visible spectroscopy. A 100 mg L⁻¹ phenol aqueous solution was used as the pollutant. The effects of calcination temperature, the dosage of butyl titanate, the dosage of catalyst and solution pH value on the photocatalytic activity of Fe₃O₄/TiO₂ were investigated. The results showed that Fe₃O₄/TiO₂ photocatalyst could be easily recovered from the solution by permanent magnet. The photocatalytic activity reached a maximum under the following conditions: calcination temperature, 400 °C; butyl titanate dosage, 10 mL; catalyst dosage, 3 g L⁻¹; and solution pH value, 2.