Synthesis of anatase TiO2 nanotubes derived from a natural leucoxene mineral by the hydrothermal method

Anatase TiO2 nanotubes were synthesized from a natural leucoxene mineral by the hydrothermal method at 105 °C over a period of 24 h. The prepared samples were calcined at various temperatures from 100 to 1000 °C in air for 2 h. The samples were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), thermogravimetry-differential thermal analysis (TG-DTA), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis to determine the specific surface area. The XRD patterns revealed that the as-synthesized samples were titanate (H2Ti3O7) nanotubes. The as-synthesized samples calcined at 400 °C showed anatase TiO2 with inner and outer diameters of ~6 nm and 16 nm, respectively, and lengths in the range of 20-100 nm. The BET surface area of the anatase TiO2 nanotubes was ~82.98 m2/g. The photocatalytic activity of the anatase TiO2 nanotubes was observed to be higher than that of commercial anatase TiO2 nanoparticles (JRC-01).