Characterization of hydrated titanium oxide with sheet-like and tube-like structures prepared by a hydrothermal processing

Hydrated titanium oxides structures have been synthesized successfully from rutile by a single-step hydrothermal process at 130 °C in NaOH at concentrations of 5 M and 10 M, monitoring up to two days. Field emission scanning electron microscopy (FEG-SEM) and transmission electron microscopy (TEM) images indicate that samples treated at 5M were composed of sheet-like structures, while nanotubes were mainly found at 10 M. XRD analysis for both concentrations indicated presence of two phases, hydrated titanium oxide not indexed yet and rutile. Besides, X-ray diffraction (XRD) patterns of the samples treated at 10 M exhibited high reflections from the nanostructures, i.e., they possess high crystallinity. Thermogravimetry Analysis (TGA) indicated that the nanostructures show crystallized water in their matrix, specifically it was found that this hydrated phase has half molecule of occluded water per unit cell. This result is consistent with Raman spectroscopy that corroborates the existence of crystallization water in the synthesized product, by a deep profile of hydrated titanium oxide.