Low temperature, organic-free synthesis of Ba3B6O9(OH)6 nanorods and β-BaB2O4 nanospindles

Using a low temperature, organic-free hydrothermal technique, single-crystalline barium polyborate Ba3B6O9(OH)(6) (BBOH) nanorods were synthesized. It was found that beta-BaB2O4 (BBO) nanospindles can be achieved by annealing the BBOH nanorods at a relatively low temperature of 810 degrees C. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize these nanomaterials. The formation mechanisms are discussed in conjunction with the crystallographic characteristics and surface energy of the BBOH nanorods and BBO nanospindles. UV-vis absorption spectra demonstrated that both BBOH nanorods and BBO nanospindles are transparent from the ultraviolet to the visible regions.