| Abstract
| - Titania nanotube aggregates with different porosities were prepared from hydrothermaltreatment on commercial TiO2 particles in NaOH followed by HCl washing. Pore structureanalysis reflects that pores of smaller sizes are mainly contributed by the nanotubes whilethose of larger sizes are contributed by the interspace region of the aggregates. Thehydrothermal treatment temperature, ranging within 110−150 °C, was shown to affect notonly the extent of particle-to-sheet conversion, and thus the resulting structures of thenanotubes, but also the anatase-to-rutile transformation at high temperatures. The surfacearea of the nanotube aggregates increases with the treatment temperature to reach amaximum of ca. 400 m2/g at 130 °C, and then decreases with further increase of thetemperature. In HCl washing, both the charge-removal rate and final state of the electrostaticcharges on TiO2 affect the rolling of TiO2 sheets into nanotubes. This demonstrates that thenanotube structure can be regulated by adjusting the washing condition. Selective catalyticreduction of NO with NH3 has been conducted to prove that the vast surface of the nanotubeaggregates is accessible to the interacting molecules.
- TiO2 nanotube aggregates are prepared from hydrothermal treatment in NaOH, followed by rinsing with HCl solutions. The size of nanotubes can be regulated by adjusting the concentration of the HCl solutions. The vast surface of the nanotube aggregates has been proved to be accessible to molecules for chemical interactions.
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