Synthesis, characterization and properties of erbium-based nanofibres and nanorods

Low-dimensional nanostructures (nanofibres, nanorods and nanolayers) can be selectively synthesized from erbium oxide hydroxide ErOOH using a facile hydrothermal method. The ErOOH nanofibres are monoclinic with diameters in the range of 6-30 nm. Some of the nanofibres grow into branches of the same size. This nanomaterial was obtained in subcritical water in a batch reactor at pH 12, temperature 300 degrees C, pressure 25 MPa and reaction time of 2-22 h. Increasing the pH to 13 under the same experimental conditions led to the production of nanorods instead of nanofibres with diameters of 20-100 nm. Decreasing the pH to 6, again with no other variation in experimental conditions, had a dramatic effect-a new crystalline phase of star-like nanolayers was formed. Subsequent dehydration of the nanofibres at 800 degrees C led to the formation of Er2O3, which had the same morphology as the nanofibres. The crystallinity, morphology and other structural features of the ErOOH-based nanomaterials have been investigated by field SEM, XRD, TEM, SAED (selected-area electron diffraction) and BET measurements of the surface area. In addition, the infrared, UV-visible and fluorescence spectra of the nanomaterials have been measured.