Persistent Fluorescence-Assisted TiO2-xNy-Based Photocatalyst for Gaseous Acetaldehyde Degradation

Photocatalytic technologies were utilized to develop an environment-friendly system that is capable of removing and oxidizing organic pollutants from an air stream. A series of long-afterglow phosphors emitting long lifetime fluorescence was adapted to prepared TiO2-based composite photocatalysts for the photodegradation of gas-phase acetalde-hyde. Although the photocatalytic reaction by an undoped titania (Degussa P25) was stopped immediately after turning off the irradiation light, the long-afterglow phosphor/nitorogen-doped TiO2 (TiO2-xNy) composites maintained the acetaldehyde photodegradation ability even after turning off the light for a long time. This novel photocatalytic property may be attributed to the presence of the long afterglow phosphor, which can reserve the light energy and generate the persistent fluorescence afterward as the light source for the photocatalytic reaction with the visible light responsive TiO2-xNy. The substitution of the undoped TiO2 with TiO2-xNy was essential to use the fluorescence as a light source for photocatalysis. Such a self-fluorescence-assisted system could enhance the performance of photocatalysts for environmental cleanup.