Synthesis of Fe₂O₃/TiO₂ nanorod–nanotube arrays by filling TiO₂ nanotubes with Fe

Synthesis of hematite (α-Fe₂O₃) nanostructures on a titania (TiO₂) nanotubular template is carried out using a pulsed electrodeposition technique. The TiO₂ nanotubes are prepared by the sonoelectrochemical anodization method and are filled with iron (Fe) by pulsed electrodeposition. The Fe/TiO₂ composite is then annealed in an O₂ atmosphere to convert it to Fe₂O₃/TiO₂ nanorod–nanotube arrays. The length of the Fe₂O₃ inside the TiO₂ nanotubes can be tuned from 50 to 550 nm by changing the deposition time. The composite material is characterized by scanning electron microscopy, transmission electron microscopy and diffuse reflectance ultraviolet–visible studies to confirm the formation of one-dimensional Fe₂O₃/TiO₂ nanorod–nanotube arrays. The present approach can be used for designing variable one-dimensional metal oxide heterostructures.