Variation of photocatalytic activity in titanium dioxide film modified by femtosecond laser irradiation

Titanium dioxide (TiO2) has a variety of functions, but cannot be activated by visible-light illumination. It is importance to extend the activity of TiO2 into the visible-light, which comprises the larger portion of the room light. Therefore, the visible-light activated TiO2 is required. We developed it with the femtosecond laser irradiation. The TiO2 films irradiated with femtosecond laser were darkened without changing topography of the TiO2 film surface. In the visible-light photocataltic function measurements, the TiO2 films were evaluated with the acetaldehyde decomposition test. The concentration of acetaldehyde was decreased to over time. This result indicated that visible-light activated photocatalyst function of TiO2 films were generated by femtosecond laser irradiation.