Synthesis and Characterization of Ultrahigh Crystalline TiO_2 Nanotubes

摘要

Ultrahigh crystalline TiO_2 nanotubes were synthesized by hydrogen peroxide treatment of very low crystalline titania nanotubes (TiNT-as prepared),which were prepared with synthesized TiO_2 nanoparticles by hydrothermal methods in an aqueous NaOH solution.Thus,prepared ultrahigh crystalline TiO_2 nanotubes (TiNT-H_2O_2) showed comparable crystallinity with high crystalline TiO_2 nanoparticles.The details of nanotubular structures were elucidated by high resolution-transmission electron microscopy (HR-TEM),field emission-scanning electron microscopy (FE-SEM),energy-dispersive X-ray analysis in transmission electron microscopy (TEM-EDX),X-ray diffraction (XRD),photoluminescence (PL),and BET surface area.TiNT-H_2O_2 was found to be a multiwalled anatase phase only with an average outer diameter of approx 8 nm and an inner diameter of approx 5 nm and grown along the [001] direction to 500-700 nm long with an interlayer fringe distance of ca.0.78 nm.The photocatalytic activity of TiNT-H_2O_2 was about 2-fold higher than those of TiNT-as prepared,synthesized TiO_2 nanoparticles,and TiO_2-P25 (Degussa) in the photocatalytic oxidation of trimethylamine gas under UV irradiation.