Influence of alkali-treatment temperature on the one-dimensional structure of nanosized TiO_2

摘要

One-dimensional titania nanomaterials were synthesized by soft chemical processes in an alkali medium. The effect of alkali-treatment temperature on the morphology, porosity, and crystalline phase of TiO_2 nanomaterials was investigated. Nanotubes having an opening end were observed when aging the sample at 130 °C, while conducting the process at 180 °C resulted in nanoribbons with a high aspect ratio. Post-treatment at 300 °C led to the partial transformation from tubular structures into nanoparticles or ribbons into nanobelts. While the monoclinic sodium hexatitanate and anatase crystal had a tubular structure, nanoribbons and nanobelt TiO_2 also showed the presence of hydrogen titanate and sodium trititanate. High surface areas were achieved in as-prepared nanotubes and nanoribbons, 456.5 and 72.1 m~2/g, respectively, and a drastic reduction was obtained upon post-treatment at 300 °C to 72.1 and 19.2 m~2/g, respectively