Porous TiO 2 nanostructures synthesized from peroxotitanic acid-derived anatase

Titania/titanate nanotubes and nanoplates were prepared by an alkali hydrothermal method using the powder and the sol of peroxotitanic acid-derived anatase, respectively, as precursors. XRD patterns and Raman spectra showed that both nanotubes and nanoplates are of titanate structure with the latter involving a slight part of anatase phase. These nanotubes and nanoplates are highly mesoporous based on nitrogen adsorption measurement. After calcination at 823 K, nanotubes were transformed into nanorods, and nanoplates into spherical particles, both of which are pure anatase-type titania. The nanorod material exhibits an enhanced photocatalytic activity in comparison with the spherical particles.