The activation of deactivated TiO2 and ZnO catalysts by exposure with clean air flow and UV radiation

Photocatalytic oxidation (PCO) is a promising method for the removal of volatile organic compounds (VOCs). Photocatalytic oxidation process, despite its advantages, has disadvantages such as deactivation of photocatalyst. The deactivated photocatalyst can be active through thermal abatement, ozonation, exposure with clean air and UV radiation.
In this paper, the deactivated TiO2 and ZnO catalysts were exposed to clean air flow and UV radiation for 6, 12 and 24 hours. After exposure, the efficiency of reactivated catalysts in photocatalytic oxidation of chloroform was examined.
The results showed that clean air flow and UV radiation can be active the deactivated catalysts. The highest and lowest removal efficiency of chloroform by reactivated catalyst was an average of about 34.50 and 10.50%, respectively. The maximum and minimum rate of activation were 34.50% and 10.50%, respectively.
The rate of activation was a function of exposure time with pure air and UV radiation. The maximum of activation achieved after 24 hour exposure.