Sterilization system for air purifier by combining ultraviolet light emitting diodes with TiO2

Abstract BACKGROUND: Ultraviolet light emitting diodes (UV LEDs) were used as a light source in TiO 2 photocatalysis because of their many advantages, such as, long life, safety, low pollution, etc. In this experiment, a light source panel was successfully fabricated with UV LEDs, the light intensities of which were relatively uniform. RESULTS: The sterilization process comprised two steps. First, an aerosol was blocked by high efficient particulate air (HEPA) filter paper coated with TiO 2 photocatalyst. Second, Staphylococcus aureus in the aerosol decreased gradually in the photocatalysis process of UV LED/TiO 2 . After 52 h irradiation all the S. aureus were killed. CONCLUSION: The UV LED light source panel had a larger surface for irradiation than a mercury lamp. Thus, its sterilization efficiency was much better than that of traditional methods. The feasibility of UV LED/TiO 2 for photocatalysis was proved. Copyright © 2009 Society of Chemical Industry