Fe₃O₄/TiO₂ core/shell nanocubes: Single-batch surfactantless synthesis, characterization and efficient catalysts for methylene blue degradation

Amorphous titania coated magnetite (Fe₃O₄/TiO ₂) nanocubes were successfully synthesized through hydrolysis and condensation of titanium isopropoxide and iron sulfate heptahydrate using single reaction sonochemical process for catalytic applications. X-ray diffractometry, transmission electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy were used to characterize the crystal structure, size and morphology, elemental composition, metal-metal and metal-oxygen bonds of the core/shell nanocubes. Magnetic properties of the samples were measured by a vibrating sample magnetometer at room temperature. Catalytic measurements on the samples showed an excellent efficiency for the degradation of methylene blue, and this efficiency was further promoted remarkably by addition of hydrogen peroxide (H₂O₂) within only 5 min of reaction time in the absence of ultraviolet irradiation. Even after recycling the sample for six times, the introduced catalyst was found to retain as much as 90% initial efficiency. A possible reaction mechanism for the sonochemical deposition of titania on the surface of magnetite nanocubes and also for the degradation process of methylene blue by the introduced catalyst was discussed.