Low-temperature sol–gel synthesis of nanosized pseudobrookite crystals without heat treatment

TiO 2 -based and Fe 3 O 4 -based nanocomposites are of interest as photocatalysts, materials for spintronics, sensors, etc. This paper presents a new approach to synthesize pseudobrookite crystallites which is based on sol–gel transformations and interaction of the multiphase colloidal system components and makes it possible to yield hydroxylated crystallites of a material that is identical to pseudobrookite according to XRD at near-room temperature without annealing stage. Using results of dynamic light scattering and low-temperature nitrogen adsorption–desorption the structural changes occurring upon the interaction of TiO 2 and Fe 3 O 4 nanoparticles in the synthesis process were studied. Comparison of the spectral characteristics of the nanocomposite consisting of titania (anatase) and magnetite in the visible and UV spectral regions showed a significant visible-region shift of the nanocomposite absorption bands compared to pure components.