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 TiO 2 nanotubes (TiO 2 NTs) with magnetite nanoparticles (Fe 3 O 4 NPs), yielding a magnetically guidable and active photocatalyst. A unique portfolio of TiO 2 NTs including single-tube, single-walled, and double-walled ones was used. Optimal conditions for uniform decoration of these nanotubes by Fe 3 O 4 NPs (two different loadings) using a wet chemical synthesis based on an oleate hydrothermal approach were found. The resulting TiO 2 NTs@Fe 3 O 4 NPs 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). Fe 3 O 4 NPs enhanced the photocatalytic activity of TiO 2 NTs under visible light. In principle, TiO 2 NTs@Fe 3 O 4 NPs could be used as magnetically guidable drug delivery system with photoinduced drug release.