title: Feasibility of silver doped TiO2/glass fiber photocatalyst under visible irradiation as an indoor air germicide.
abstract: This study investigated the feasibility of using Ag-TiO2 photocatalyst supported on glass fiber (Ag-TiO2/GF) prepared by a sol-gel method as an indoor air germicide. An experimental model was designed to investigate the bacterial disinfection efficiency of Staphylococcus (Staph), the most popular bacterium in hospitals in Korea, by the Ag-TiO2/GF 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 (TiO2/GF) for photocatalytic disinfection of Staph. This study confirmed that Ag in Ag-TiO2/GF could work as an electron sink or donor to increase photocatalytic activity and promote the charge separation of electron-hole pairs generated from TiO2 after photon absorption. Ag also acts as an intermediate agent for the transfer of photo-generated electrons from the valence band of TiO2 to an acceptor (O2 gas) to promote photo-oxidation processes. The photocatalytic disinfection activity of Ag-TiO2/GF 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 Staph using 7.5% Ag-TiO2/GF were 75.23% and 20 (CFU∙s-1∙cm-2) respectively. The medium level of humidity of 60% ± 5% showed better photocatalytic disinfection than the lower (40% ± 5%) or higher (80% ± 5%) levels.
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Daehakro 93, Namgu, Ulsan 680-749, Korea. thanhdongpham080808@gmail.com.
authors.forename: Thanh-Dong
authors.initials: TD
authors.lastname: Pham
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Daehakro 93, Namgu, Ulsan 680-749, Korea. bklee@ulsan.ac.kr.
authors.forename: Byeong-Kyu
authors.initials: BK
authors.lastname: Lee
mesh_terms: D016902:Air Pollution, Indoor / Q000517:prevention & control*; D002384:Catalysis; D004203:Disinfection / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005898:Glass; D006813:Humidity; D008027:Light; D008855:Microscopy, Electron, Scanning; D056951:Photoelectron Spectroscopy; D012834:Silver / Q000528:radiation effects*; D013056:Spectrophotometry, Ultraviolet; D013210:Staphylococcus; D014025:Titanium / Q000528:radiation effects*; D014961:X-Ray Diffraction
chemical_list: C009753:fiberglass; C009495:titanium dioxide; D012834:Silver; D014025:Titanium