Photocatalytic Properties of Nanotubular-ShapedTiO2Powders with Anatase Phase Obtained from Titanate Nanotube Powder through Various Thermal Treatments

Abstract

Photocatalytic properties of nanotubular-shaped titanate powders, synthesized by hydrothermal treatment ofTiO2, were studied after calcinations at various temperatures and times underO2, air, and H2atmospheres. Their photocatalytic properties were measured with checking decomposition of 4-chlorophenol under UV-A irradiation, together with physical characterizations using SEM, TEM, XRD, BET, and Raman spectroscopy. With increasing calcination temperature and time, nanotubular-shaped titanate particles became short, rod-like, or irregular by oversintering, and their crystalline structure was changed into anatase phase. The photocatalytic ability in decomposition of 4-chlorophenol using the calcined powders showed the highest value due to obtainment of high specific area by maintaining nanotubular shape, together with transformation from titanate to anatase phase having perfect crystallinity inO2or air atmosphere.