Preparation and Characterization of Flowerlike Y2(OH)5NO3·1.5H2O and Y2O3 and Their Efficient Removal of Cr(VI) from Aqueous Solution

A simple sonochemical procedure was developed to synthesize the flowerlike yttria precursor Y 2 (OH) 5 NO 3 ·1.5H 2 O. Y 2 O 3 with the same morphology was readily obtained by calcination of the precursor. The microstructures and morphologies of the products were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and field-emission scanning electron microscopy (FESEM). The as-obtained Y 2 O 3 and its precursor were found to be effective sorbents for the removal of Cr(VI) ions in water treatment, as a result of the novel hierarchical structures and high specific surface areas of these two materials.