One-Step Decoration of TiO₂ Nanotubes with Fe₃O₄ Nanoparticles: Synthesis and Photocatalytic and Magnetic Properties

This paper presents an effective hydrothermal route to decorate various types of anodic 1D TiO2 nanotubes (TiO2 NTs) with magnetite nanoparticles (Fe3O4 NPs), yielding a magnetically guidable and active photocatalyst. A unique portfolio of TiO2 NTs including single-tube, single-walled, and double-walled ones was used. Optimal conditions for uniform decoration of these nanotubes by Fe3O4 NPs (two different loadings) using a wet chemical synthesis based on an oleate hydrothermal approach were found. The resulting TiO2NTs@Fe3O4NPs were shown to be superparamagnetic at room temperature, to have a stable connection of NPs to NTs, and to have good magnetic response under an external applied magnetic field. The as-prepared materials were used as magnetically guidable photocatalyst for the decomposition of a model dye (methylene blue). Fe3O4 NPs enhanced the photocatalytic activity of TiO2 NTs under visible light. In principle, TiO2NTs@Fe3O4NPs could be used as magnetically guidable drug delivery system with photoinduced drug release.