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

Abstract

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.