Hydrothermal Synthesis of H-Ti-O Nanotubes and Their Structural Evaluation
Takashi KUBO, Tetsuo HONMA, Masanori UMESAKI and Atsushi NAKAHIRA
Abstract:The nanotubular products were synthesized by hydrothermal treatments of anatase-type TiO2 in NaOH aqueous solution. In order to clarify the consolidation of nanotube, the effect of several washing treatments with deionized water, HCl solution, or dehydrated ethanol, on the structure and the composition of nanotubes was investigated in this study. Especially, the characterization of microstructure of these nanotubular products was examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray absorption fine structure (XAFS). As a result, it was found that nanotubes were formed during the hydrothermal treatments, not during the washing treatments. In addition, it was clearified that the nanotubes were composed of layered Na-Ti-O, and H-Ti-O nanotubes were obtained by ion-exchange of Na+ for H+ in Na-Ti-O nanotubes by washing with deionized water or anhydrous ethanol and successively with HCl solution. Key Words:H-Ti-O, TEM, XANES, X-ray absorption fine structure, Microstructures