A simple and low-temperature hydrothermal route for the synthesis of tubular alpha-FeOOH

Abstract

Tubular alpha-FeOOH was synthesized via hydrothermal reaction at 120 degrees C. X-ray diffraction (XRD) pattern indicates that the as-prepared sample is the pure orthorhombic phase alpha-FeOOH. Fourier transform infrared (FT-IR) analysis further confirms the formation of orthorhombic phase alpha-FeOOH. The morphology and structure of the as-obtained product were characterized by transmission electron microscopy (TEM) techniques. TEM images show a high degree of contrast between the bright central part and the darker edges, demonstrating the hollow core of the product. The obtained tubular alpha-FeOOH was similar to 10 nm in outer diameter and similar to 6 nm in inner diameter, respectively. High-resolution TEM image of one single nanotube shows the clearly resolved interplanar spacing of about 4.18 angstrom, which corresponds to the spacing between (110) planes of the orthorhombic-type alpha-FeOOH crystal. The room-temperature UV-Vis absorption spectrum of the tubular alpha-FeOOH nanostructures is presented. (C) 2007 Elsevier B.V. All rights reserved.