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

BACKGROUND: Ultraviolet light emitting diodes (UV LEDs) were used as a light source in TiO2 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 TiO2 photocatalyst. Second, Staphylococcus aureus in the aerosol decreased gradually in the photocatalysis process of UV LED/TiO2. 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/TiO2 for photocatalysis was proved.