Preparation Of Functional Composite Fibers For Application In Water Purification

With the progress of society,the people’s living standard has been continuously improved,however,water pollution during to metal ions and organic compound in industry wastewaters has become a worldwide serious environmental issue.Most of the metals ions and organic compounds which have high toxic and nonbiodegradable properties,are released into the environment in quantities that pose a risk to human health.Degradation of toxic organic pollutants in water or air has received considerable attention over recent years.Recently,in order to ease the pressure of water pollution,there are many approach to deal with pollutants,such as,biological treatment with enzyme or micro organism,physical treatment of wastewater with flocculating agent and photocatalytic treatment with catalysts.However,due to the conditions of biological treatment are harsh,especially microbial and enzyme on the environment（such as temperature,pH value and so on）the requirements are relatively high,small changes can inactivate enzymes or microorganisms to loss of life activity,which limits their application scope.In resent years,adsorption by natural occurring materials has shown to be one of the most efficient and low cost methods for metal removal from aqueous solution.And semiconductor photocatalysis has been widely investigated for its potential application in environmental protection and solar energy transformation.TiO₂ acted as a semiconductor photocatalyst has been obtained a large number of scientific researcher’ attention and got a mass of experimental results during the forty decades since Fujishima and Honda discovered TiO₂ photochemical electrode in 1972.It is expected to be one of the most valuable photocatalysts due to its oxidative,chemically stable,economical and non-toxic characteristics.However,TiO₂ can’t effectively utilization of solar light,which drives us to make numerous efforts to explore other novel efficient visible light photocatalysts for the better utilization of solar light through two ways,including coupling other semiconductors with TiO₂ and exploitation of new nontitania-based visible-light photocatalysts.According to above background,the main contents of this paper are listed as follows:1.We presented a fast,environment-friendly and facile method for preparation of chitosan and urea modified fluorinated graphene（FG）composite fiber and evaluated its adsorption performance toward Ni（II）,Cd（II）and Cu（II）ions from aqueous solutions.Basically,the initial surface functionalization of FG was conducted to change its surface wettability.Then,chitosan and FG composite fibers were prepared using a wet spinning method.The characterization tests of FTIR,SEM and tensile performance were conducted to investigate the chemical and morphological changes and mechanical properties of the composite fibers.The biocompatibility and antibacterial effect of the composite fibers were investigated.The adsorption behaviors toward Ni（II）,Cd（II）and Cu（II）ions from their aqueous solutions were also studied.2.We chose a green and environmentally friendly electroless plating technique to prepare the composite nanofibers materials as photocatalysts degradation of rhodamine-B（Rh B）under the visible-light irradiation and at room temperature.Although the similar composition of nanofibers have been prepared by our group,the composite carbon nanofibers（CNFs）with hierarchical nanostructures of BiOBr/AgBr were obtained by a simplified process,including adding the certain amount of BiOBr/AgBr precursors into the spinning solution and following electrospinning and carbonization treatments.The as-prepared composite CNFs exhibited highly photocatalytic activities for degradation of Rh B under the visible-light irradiation and at room temperature.Furthermore,the as-prepared composite CNFs showed the favor separation,recovery,and cyclic utilization properties.3.We chose the carbon nanofibers as the catalyzer carrier,and the composite nanofibers containing Cu₂O precursor was successfully prepared by electrospinning with copper acetate as the copper source.Then the carbon nanofibers were carbonized to obtain Cu₂O/CNFs composite nanofibers.The composite carbon nanofibers were applied to degradate organic dye and phenol in wastewate.It exhibited high photocatalytic activity for Rh B degradation under visible light irradiation.The composite carbon nanofibers preparation method has obvious advantages such as simple preparation process,easy loading of the catalyst on the carbon nanofibers and the catalyst particles were fixed inner the fibers which tough,thus solving the problem that the conventional powdery catalyst is difficult to be recovered.