In this paper, both nanotubes and nanowires were synthesized directly using a cheap precursor (low surface area TiO2) via a simple hydrothermal process without using any sacrificial templates. The synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microcopy (TEM), and accelerated surface area and porosimetry apparatus (ASAP). Transmission electron microscope observations showed that nanotubes were formed with an inner diameter of 2-3.5 nm, an outer diameter of 8-10 nm, and an open-ended shape. The nanotubes showed IV-type isotherms with 143 type hysteresis loop according to BDDT (Brunauer, Deming, Deming, and Teller) classification, indicating the presence of mesopores. Significant increases of specific surface area (277.82 m(2)/g) and pore volume (1.08 cm(3)/g) have potential applications such as in catalysts, sensors, high efficient solar cells, for hydrogen storage, as absorbents, etc. With an increase in the hydrothermal temperature, the morphology transformed to nanowires and the surface area and pore volume decreased.

Keywords: Nanostructure; Hydrothermal; Nanotube; Titanate; Nanowire