Masayuki Aonuma

The Preparation of Porous TiO2 by Immersing Ti in NaOH Solution

The formation of a porous TiO 2 layer by immersing Ti in 5 M NaOH at 303 K was investigated using electrochemical measurements, a scanning electron microscope, and grazing incident X-ray diffraction. The porous layer was readily obtained in the case of the presence of titanium hydride (TiH 2 ) on the surface before immersion. The crystalline structure of the porous layer is composed of a mixture of the rutile and anatase type TiO 2 . The porous layer is hard to produce without the presence of TiH 2 . TIte TiH 2 is directly changed to TiO 2 by a dissolution reaction in alkaline solution. The presence of TiH 2 on the surface is an important factor for the preparation of the porous TiO 2 layer.