Titania nanowires functionalized polyester fabrics with enhanced photocatalytic and antibacterial performances

Flexible organic fabrics coated with titania find wide applications in pollutant degradations and antibiosis. Because of the enhanced charge separations, TiO₂ with one-dimensional nanostructures exhibits photocatalytic activity superior to that of nanoparticulate films; however, only the later has been achieved on organic substrates through commonly sol-gel techniques till now. In this study, radially aligned TiO₂ nanowires were precipitated on polyester fabrics through multi-steps of surface roughening, sol-gel TiO₂ seeding, hydrogen titanate nanobelts precipitation, and finally sulfuric acid treatment. Both mesoporous anatase TiO₂ nanowires and single-crystalline rutile TiO₂ nanorods have been achieved, which, together with some unchanged titanate nanobelts, exhibited an overall narrowed band gap of ca. 2.50eV. The TiO₂ nanowires on flexible PET fabrics showed higher photocatalytic activity towards degradations of not only rhodamine B in water but also toluene gas in air under UV light illumination, when compared with either TiO₂ nanotube array or commercial Degussa P25 nanoparticulate films on metallic Ti substrates. Remarkable sterilization of E. coli and S. epidermidis under visible light irradiation was also achieved. The excellent photocatalytic and antibacterial performances were attributed to the unique mixed 1D nanostructures, phase junctions, abundant surface hydroxyl groups, and the narrowed band gap.