Recent Developments in TiO2 Photocatalysis: Novel Applications to Interior Ecology Materials and Energy Saving Systems

Although building materials coated with photoactive TiO2show remarkable self・cleaning and anti-fogging effects outdoors by absorbing UV rays from the sun，they do not function indoors．This is because the UV light intensity indoors is too weak for a simple TiO2coating to exhibit either photocatalysis or photo-induced hydrophilicity．In order to obtain interior photoactive building materlals，herein we report three different types of materials based on TiO2， which can function even under room light conditions．First is a TiO2film deposited with Cu that shows a remarkable antibacterial effect since the TiO2photocatalytic reaction assists the intmsion of antibacterial copper ions into cells． Thus，even very weak UV light is suf6cient to lower cell activity．Second is a layered TiO2／WO3heterogeneous且1m， which becomes highly hydrophilic even under nuorescent light since the photo-generated holes produced in WO3by U▽1ight are transferred to the TiO2side and then used for hydrophilic conversion．Third is a nitrogen doped TiO2 film，which can be highly hydrophilic by absorbing only visible light．In addition，we demonstrate a novel application