Indoor air germicide feasibility of silver doped TiO2/glass fiber photocatalyst under visible irradiation

摘要

This study investigated indoor air germicide feasibility of photocatalyst Ag-TiO2 supported on glass fiber prepared by a sol-gel method. A experimental model was designed to investigate bacterial disinfection efficiency of Staphylococcus, the most popular bacteria in hospital in Korea, by Ag doped TiO2/glassfiber photocatalyst. The silver content in Ag/TiO2 was altered from 1 to 10% to investigate the optimal ratio of Ag doped on TiO2/glass fiber for photocatalytic disinfection of Staphylococcus. This study confirmed that Ag in Ag doped TiO2/glass fiber can work as an electron sink or donor to increase photocatalytic activity and can also promote the charge separation of electron-hole pairs generated from TiO2 after photon absorption. Also, Ag acts as an intermediate agent for the transfer of photo-generated electrons from valance band of TiO2 to an acceptor (O2 gas) to promote for photo-oxidation process. The photocatalytic disinfection activity of Ag doped TiO2/glass fiber under visible light increased with the increase in silver content up to 7.5% and then slightly decreased with further increasing silver content. The highest disinfection efficiency and disinfection capacity of Staphylococcus using 7.5%Ag-TiO2/glass fiber were 75.23% and 20 CFU/s.cm2, respectively. The medium level of humidity of 60+5% showed better photocatalytic disinfection than the lower (40+5%) or higher (80±5%) levels.