Effect of Photoetching on Photoinduced Hydrophilicity of Titanium Dioxide Film

抄録

The effect of photoetching (photoelectrochemical etching) on photoinduced hydrophilic conversion of titanium dioxide (TiO₂) film electrodes prepared by thermal oxidation of Ti plate has been studied. We have found that photoetching of TiO₂ film results in the formation of nano-porous structure depending upon preparation condition (oxidation temperature), photoetching condition (electrode potential) and crystallographic orientation of the TiO₂ grain. Photoetching of the film oxidized at temperature higher than 900°C makes nano-porous structure consisting of (100) plane of rutile structure of TiO₂ and improves the photoinduced hydrophilic conversion property. Photoetching under anodic polarization increases the rate of photoinduced hydrophilic conversion, while the film photoetched under weak anodic polarization does not show the photoinduced hydrophilic conversion property.