Fabrication of mesoporous bulk composed of titanate nanotubes by hydrothermal hot-pressing technique

In this study, bulky titanate nanotubes with dense microstructures were successfully fabricated by a hydrothermal hot-pressing (HHP) technique with water as a reactive solvent. Titanate-based nanotubes of about 10 nm outer diameter and 5 nm inner diameter and a few hundred nanometers in length were synthesized by a hydrothermal treatment of anatase-type TiO₂ powder in a 10 M NaOH aqueous solution. From results of N₂-adsorption and transmission electron microscopy observation, it was obvious that HHP processed samples were composed of nanotubular structures and that the obtained bulks possessed mesopores and high Brunauer–Emmett–Teller surface area. These results suggested that the obtained bulks possessed functionality as good as that of powders of titanate nanotubes. Thus, the HHP technique may be a useful method for fabricating bulky titanate nanotubes and may be applied in the solidification of the other some nanotubular materials.