Synthesis and Characterization of Thermally Stable Nanotubular TiO₂ and Its Photocatalytic Activity

Abstract

Hydrogen titanate nanotubes obtained by hydrothermal synthesis are treated with sol containing titanium. The products are characterized with transmission electron microscopy, X-ray diffraction, thermal gravimetric analysis, and Raman spectroscopy. Their photocatalytic performance is evaluated by the photocatalytic degradation rates of methyl orange in aqueous solution under UV-vis light irradiation. The results reveal that the treated nanotubes are more thermally stable and exhibit better photocatalytic performance than primary nanotubes. The treated nanotubes can keep a tubular structure when calcined at 400 °C. However, their precursors collapse when they are calcined only at 300 °C. The more thermally stable new functional TiO 2 nanotubes can be prepared by using sol containing other elements instead of sol containing Ti in the future.

Preparation and Photocatalytic Performance of Anatase/Rutile Mixed-Phase TiO2 Nanotubes

“…However, the photocatalytic activities of the hydrothermally synthesized TiO 2 -derived nanotubes are not as high as expected because of containing minor photocatalytic active anatase phase [4]. When trying to get more anatase phase by annealing at higher temperature, the nanotubes will collapse [5]. Many efforts have been dedicated to improving the photocatalytic activities of TiO 2 -derived nanotubes, such as coating mesoporous titania nanorods [6], treating with titania sol [5] and chemical morphology freezing treatment [7].…”

“…When trying to get more anatase phase by annealing at higher temperature, the nanotubes will collapse [5]. Many efforts have been dedicated to improving the photocatalytic activities of TiO 2 -derived nanotubes, such as coating mesoporous titania nanorods [6], treating with titania sol [5] and chemical morphology freezing treatment [7]. Commercial TiO 2 nanoparticles (Degussa P25), consisting of mixed 80% anatase and 20% rutile phases, has been proven to be an excellent potential photocatalyst [8].…”

Simultaneous Enhancement of Photocatalytic Bactericidal Activity and Strength Properties of Acrylonitrile-Butadiene-Styrene Plastic Via a Facile Preparation with Silane/TiO2

“…The photocatalytic improvement could be plausibly explained by a higher degree of crystallinity as mentioned earlier. That is, the more-active crystal phase was improved and surface defects were reduced as documented by several studies [23][24][25][26]. However, when increasing calcination temperature up to 800 • C, the photoantibacterial performance decreased.…”

Acid Properties of Protonated Titanate Nanotubes

“…The synthesis process is an inexpensive onestep reaction that requires neither expensive apparatus nor special chemicals. Titanate nanotubes have been widely employed in the design of photocatalytic systems 6), 7) , catalyst supports 8), 9) , lithium batteries 10), 11) , and photoelectrochemical cells 3), 12) due to their unique physico chemical properties and unusual morphology. The proposed formation mechanism of the titanate nanotubes 3),13) 15) is shown in Fig.…”