Anatase TiO₂ Nanoparticle Coating on Barium Ferrite Using Titanium Bis-Ammonium Lactato Dihydroxide and Its Use as a Magnetic Photocatalyst

Photoactive anatase TiO 2 nanoparticles with a size less than 10 nm were coated on barium ferrite forming complete coverage by the controlled hydrolysis and condensation of titanium bis-ammonium lactato dihydroxide in the presence of polyethyleneimine at a relatively low temperature (95 °C). The as-prepared composite particles (hard magnetic barium ferrite (core)−anatase TiO 2 nanoparticles (shell)) can be utilized as a magnetic photocatalyst, which can be fluidized and recovered by an applied magnetic field enhancing both the separation and mixing efficiency for remediating fluids. The morphology of composite particles was characterized with scanning electron microscopy and transmission electron microscopy. The crystalline structure of TiO 2 was characterized by X-ray diffraction and electron diffraction. Energy-dispersive spectroscopy was utilized for the elemental analysis of the products. The as-prepared TiO 2 −barium ferrite composite has higher photocatalytic activities than the TiO 2 −barium ferrite composite heat-treated at 500 °C for 1 h. The higher photoactivities of the unheated composite are ascribed to higher specific surface area and preservation of the surface hydroxyl groups on TiO 2 .