Photocatalytic Self-cleaning by Nanocomposite Fibers Containing Titanium Dioxide Nanoparticles

Titanium dioxide (TiO ₂ ), a well-known photocatalyst, was incorporated into poly(vinyl alcohol) (PVA) nanofibers via electrospinning to develop self-cleaning textile materials that can decompose organic contaminants and stains on the textile surface by light irradiation. TiO ₂ /PVA nanocomposite fiber webs were prepared from PVA solutions that contained 5, 10, and 20 wt% TiO ₂ nanoparticles. The morphologies and chemical compositions of the composite fibers were characterized using scanning electron microscopy, transmission electron microscopy, and an energy dispersive X-ray analysis system. The TiO ₂ /PVA nanocomposite fiber webs were thermally treated to increase their stability in an aqueous environment. To evaluate the self-cleaning performance, the fiber webs were saturated using a methylene blue dye solution and red wine. Different light sources, i.e., ultraviolet (UV) light, visible light, and fluorescent light, were used to examine their effects on the photocatalytic self-cleaning activities of the TiO ₂ /PVA nanocomposite fiber webs. The color changes of the methylene blue and red wine stains on the fiber webs were assessed with the time of light exposure over a period of 24 h. The results depicted that the decomposition rates of the methylene blue and red wine stains by the fiber webs varied in the order of fluorescent light < visible light < UV light. Generally, the decomposition rate increased by increasing the time of light exposure and the TiO ₂ concentration. Our findings demonstrated the self-cleaning performance of the electrospun composite fibers containing TiO ₂ nanoparticles not only under UV light but also under visible and fluorescent light that are commonly used indoors.