The Preparation And Properties Of ZnO Coated Carbon Nanoifbers

ZnO functionalized carbon nanofibers were prepared by electrospinning, sol coating and carbonizationtechnology. Firstly, the precursor of carbon nanofibers were prepared by electrospinning withpolyacrylitrile and zinc acetate; then, ZnO sol were prepared and coated on the surface of polyacrylonitrilenanofibers; next, ZnO coated nanofibers were preoxided and carbonized to prepare ZnO coated carbonnanofibers. The proporties of ZnO coated carbon nanofibers were studied in antibacterial, adsorptionand photocatalytic, respectively. Finally, the Fe2+ions were coated on the C/ZnO nanofiber by dipcoating to improve the photocatalytic properties of the C/ZnO nanofibers.The experimental results showed that with zinc acetate content increase and PAN content decrease, theviscosity of spinning solution decreases, the surface tension and electrical conductivity of spinningsolution increases, the volatile of spinning solution weakened. The results of FTIR and gaussian quantummechanical simulation revealed there were existed weak hydrogen bond between zinc acetate andpolyacrylonitrile. The results also showed with dihydrate zinc acetate content in spinning solutionincrease, the diameter of nanofibers seems smaller, the surface of nanofiber looks much rougher and theaggregation effect of zinc acetate in the fiber was more obvious.ZnO sol was prepared by adding dihydrate zinc acetate in a mixture of ethanolamine and ethanol at60℃, and then ZnO sol was deposited on PAN nanofibers substrates by coating technique. The ZnO soladsorption of nanofibers substrates was decided by surface tension, sol density, viscosity and membranesurface contact angle. The adsorption capacity was proportional to the sol density, surface tension andmembrane surface angle, and was inversely proportional to the viscosity of the sol. In this study, the thick-ness models of sol coated nanofiber membrane were builded through analyzing the fluid force. Thethickness of sol coating nanofiber membrane can be obtained from the formula K1ηv/h=ρgh+γcos（π-θ）.CycLization, deoxidation and dehydrogenation reaction were be founded during Preoxidation at240℃,and the nirregular crystal structure of zinc oxide nanoparticles was formed on the fiber surface by thethermal decomposition of ZnO gel. ZnO gel was decomposed into the structural integrity of nano-zincoxide during carbonation at350℃. At the same time, a large number of polyacrylonitrile convertedto carbon. The experimental results showed that with increasing carbonization temperature, the crystalstructure of zinc oxide on fiber surface become regular, and its grain increase, the grain growth momentumequation under these conditions was LnD=3.64337-0.69526/T.Specific surface area measurements and methylene blue adsorption test revealed that adsorptionproperties of ZnO coated carbon nanofiber was relatively small. Antibacterial experimental results showedthat ZnO coated carbon nanofiber had good resistance to E.coli. The photocatalytic results indicated thatthe carbonization temperature, the zinc acetate content in carbon nanofiber precursor and the coatingconcentration of zinc oxide sol had a certain impact in photocatalytic properties of ZnO coatedcarbon nanofibers. ZnO coated carbon nanofibers showed certain photocatalytic and better regenerationperformance.The experimental results showed that the photocatalytic performance was improved significantly afterFe²⁺functionalized C/ZnO nanofibers. Impregnated Fe2+ion concentration, H2O2dosage and pH wereimportant to photocatalytic. In addition, the results showed that the photocatalytic could be improved bythe synergistic effect of zinc oxide and Fe²⁺.