Electrostatic Spinning Preparation Of TiO₂ Fiber And Its Photocatalytic Performance

The titanium material has been widely applied in various fields as a "star" material, especially in the photocatalysts for degradation organic materials dissolved in water. TiO2 is one of the photocatalyst-semiconductor materials, which has three crystal structures conventionally, such as Brookite, Antase and Rutile structures. Furthermore, the Anatase titanium dioxide was popularly used in the field of photocatalyst for the high efficiency, environment friendly and non-toxic during the process of applications. However, there were some shortcomings, for examples, the low quantum efficiency and absorbent in UV illumination, which greatly restrict the industrial production of titanium dioxide.In this paper, we improved the photocatalytic activity via modification for the surface of TiO2 fibers. We resorted to electrospinning technique to generate TiO2 fibers. During the process of preparation of fibers, the Tetrabutyl titanate was used as the titanium source, anhydrous methanol as solvent and polyvinylpyrrolidone(PVP) as the based-material. The mixed solution was added drops of glacial acetic acid to avoid hydrolysis of tetrabutyl titanate. The feeding rate of the solution in the syringe was controlled at 1.0 mL h-1. The voltage applied to the needle of the syringe was 12 kV and the distance from the tip of the needle and the aluminum foil collector was 15 cm in a fume hood in air with the humidity below 40%. Subsequently, the obtained nonwoven membrane was calcined at 520℃ for 2 hours. In order to get high quantum efficiency and the wider light absorption range of photocatalytic titanium dioxide nano materials, the TiO2 nanofibers were modified by copper oxide and silver nanoparticles respectively. Then, the as-prepared samples were characterized by XRD, SEM, TEM and other measurements respectively. The photocatalytic property of the sample was tested via rhodamine B degradation and the sample showed the obvious catalytic activity for the degradation of the simulation of pollutants. Furthermore, the photocatalytic mechanisms of the samples were expounded rationally at the end of the study.In the process of preparation for CuO/TiO2 fibers, we found that the alkali source had great impact on the structure and morphology of products. When ammonium hydroxide was used as alkali source, the CuO would be produced in the large scale on the surface of TiO2 fibers, whereas, the non-shaped nanoparticles were adhered on the surface of TiO2. In the photocatalytic performance of the test, compared with no treatment of TiO2 nanofibers, compound semiconductor under the same conditions for the degradation of Rhodamine B effect was about 95%. And after 5 times reused, the degradation efficiency was still kept in 91.2%. The nanoparticles of silver had greatly improved the photocatalytic performance from 76% to 98.9% under same conditions comparing with that of pure TiO2. We used PVA as stabilizer in the hydrothermal process, which had important usage in controlling the size of Ag particles.