Fabrication of TiO2-coated Porous Silica Glass Tube and Evaluation as Environmental Purification Unit

We fabricated TiO2-coated porous silica glass tubes containing macropores and evaluated their environmental purification capacity. We used two TiO2 coating methods: outside vapor deposition (OVD), and TiO2 precursor impregnation and calcination onto silica layers. The tubes exhibited air and water purification capabilities. Through a waterborne pathogens removal test, we confirmed that Escherichia coli and Legionella pneumophilia could be eliminated by filtration, even in conditions without UV-C irradiation. Moreover, the tube coated using OVD and irradiated with a UV-C lamp showed the highest Qβ reduction efficiency. The acetaldehyde decomposition properties under high-concentration conditions were outstanding (78% at 700 ppm). From methylene blue decomposition tests, we concluded that the efficiency of TiO2 photocatalytic decomposition was affected by multiple parameters, including the presence of anions and cations, as well as the solution pH.