Self-template formation and properties study of Cr2O3nanoparticle tubes

Abstract

As an important semiconductor, Cr₂O₃ exhibits many attractive properties and significant industrial applications. Nevertheless, it remains a challenge to develop a simple synthetic methodology for the fabrication of Cr₂O₃ 1D nanostructures. In this paper, Cr₂O₃ sub-microtubes, consisting of nanoparticles, have been successfully prepared by the in situreduction of SrCrO₄ nanorods in a microemulsion system. X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy were employed to study the crystal structure and morphology of the products. Experiments showed that the solvent, reaction temperature and reaction time were critical for the formation of the Cr₂O₃ nanoparticle tubes. Magnetic properties of the products were investigated by the electron spin resonance and superconducting quantum interference device magnetometer. These magnetic results revealed a weak ferromagnetic behavior induced by the uncompensated surface spin below T_B. The UV-Vis absorption spectrum showed three broad absorption peaks at 360, 450 and 600 nm, respectively. The nitrogen adsorption-desorption measurement was used to determine the surface area and pore size distribution of the as-obtained polycrystalline tubes. A possible growth mechanism for the Cr₂O₃ nanoparticle tubes was also proposed.