Synthesis of Three-Dimensional Hierarchical Dendrites of NdOHCO₃ via a Facile Hydrothermal Method

Abstract

Dentritic neodymium hydroxycarbonate NdOHCO3 nanostructures have been successfully prepared using a facile hydrothermal approach, by the reaction of neodymium nitrate and ammonium hydrogen carbonate without the assistance of any surfactants or templates. The influences of the ratio of neodymium nitrate/ammonium hydrogen carbonate, and different reaction times and temperatures have been discussed. The as-obtained superstructures are characterized by several techniques, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and fluorescence spectra measurements. The three-dimensional (3D) dentritic NdOHCO3 nanostructure is composed of one trunk with the diameter of about 50 nm and the length of about ca. 1−5 μm. And every branch is also a small dentritic nanostructure. The length of the secondary and tertiary sharp branches is about 300 nm to 2 μm and 100−300 nm, respectively. The photoluminescence (PL) spectra of the product shows an intensive band centered at about 388 nm. The relative peak intensity decreases as the reaction temperature increased and reaction time decreased. The possible formation mechanism of the 3D dentritic NdOHCO3 superstructures is proposed and discussed.