Preparation And Properties Of Electrospun Carbon Nanofibers And Their Composites

Carbon fibers are dominant in high strength, high modulus, low-density materials, they have good thermostability and resistance to corrosion, they have perfect electrical and thermal conductivity properties; Preparation of carbon nanofibers by electrospinning have unique one-dimenstional nanostructure and large length to diameter ratio. The various excellent performance of carbon fibers made them have gained a wide range of applications. At the same time, to use carbon nanofibers as supports materials prepare composites have also become an important research direction.Metallic oxide semiconductor photocatalysts, as a green technique, have attracted much attention due to their widely applicability in treatment of environmental pollution, degrade the organic pollutants in air and water. The photocatalytic reaction was deeply influenced by the electronic-hole pair. Degrade photogenerated electron-hole pair recombination should be achieve a higher photocatalytic activities. Zinc oxide (ZnO) is an important multifunctional n-type semiconductor. Due to their wide band gap energy, they should be the ideal photocatalysts.In this paper, Carbon nanofibers were prepared by the stabilization and carbonization of polyacrylonitrile (PAN) nanofibers which were obtained by electrospinning technique. The fibers under different temperatures were characterized by Scanning electron microscopy, FT-IR, XRD, Raman, respectively. Then CFs are used as catalyst supports were immersed in concentrated HNO3 result in various functional groups on their surfaces. These functional groups change the wettability of CFs changes from superhydrophobicity to hydrophilicity. The result was evaluated by the measurement of contact angle (CA). After activation of the surface of carbon fibers, several of functional groups growth on carbon fibers, and they provide the active site for photocatalyst.In this paper, Zinc oxide (ZnO) nanorods have been successfully grown on carbon fibers which were treated by HNO3 using hydrothermal technique and vapor transport deposition, respective. CFs/ZnO composites are used as photocatalysts. Carbon fibers are increasing the photocatalytic activity of ZnO. The main reason can be concluded as follows: In the first, they have one-dimenstional nanostructure, large specific surface area, carbon fibers as the fixed bed, made the photocatalyst dispersed in solution. The phenomenon of local aggregation can not appear. Moreover they create many active sites for the photocatalytic degradation. Second, charge transfer of ZnO by CFs made the recombination of photoinduced electron-hole pairs was hindered.