Light-Stimulated Composition Conversion in TiO2-Based Nanofibers

Silver−TiO 2 nanofibers (Ag/Ti = 1/50) were fabricated by the electrospinning method, followed by heat treatment at 200 °C and calcination at 550 °C. The electrospinning solution was comprised of AgNO 3 and titanium tetraisopropoxide (TTIP) with polyvinylpyrrolidone (PVP). Alternating irradiation of the silver−TiO 2 nanofibers with ultraviolet and visible light can interconvert the silver species on the TiO 2 -based nanofibers to yield Ag metal and Ag 2 O, respectively, and this process has been characterized by UV−visible spectra, TEM, XRD, and XPS. The interconversion process can be rationalized in terms of the photoreduction of Ag 2 O by TiO 2 and the oxidization of Ag by visible light. Acetaldehyde photodecomposition measurements indicate that Ag 2 O has better mineralization ability than Ag 0 in this kind of silver−TiO 2 nanofiber photocatalytic system. The photoinduced conversion of composition on TiO 2 -based nanofibers may find applications in photocatalysis, antibacterial technology, and other areas.