Fabrication And Photocatalytic Property Of TiO₂-based Nanofiber Composite Materials

With the increasing pollution of environment, using photocatalytic technology to solve environmental problems has received lots of attentions. In this paper, we aimed at the solve problems in the field of semiconductor photocatalysts, which photocatalytic efficiency is low and the materials recycling are difficult. Based on nanofibers and TiO2 have their advantages and disadvantages, respectively, we compounded them by loading TiO2 nanoparticles on nanofibers to improve the photocatalytic activity and solve the recycling issue. We synthetized a series of TiO2-based nanofiber composite materials by surface loading and modification. And we used Congo Red and methyl orange as the simulation pollutants to be degraded to study the photocatalytic properties of each nanofiber composite materials. And we also studied the influence factors of photocatalytic activity of nanofiber composite materials, like the adding amount of nannofibers, or the weight ratio of nanofibers to TiO2 nanoparticles. A series of studies on materials synthesis, modification and applications have been studied. The details are summarized as follows:(1) FMO/C@TiO2 nanofiber composite materials: In this part, One-dimensional FMO/C@TiO2 core-shell composite nanofibers with porous structure have been synthesized via a two-step solvothermal method. The main raw materials are tetrabutyl titanate, ferric sulfate, manganese sulfate and Nitrilotriacetic acid. And we have characterized the FMO/C@TiO2 nanofiber composite materials by X ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and UV-visible spectroscopy(UV-Vis) to study the phase composition, microstructure and properties of light absorption properties of the as-prepared photocatalysts. The photocatalytic properties and optical properties of them also have been detected. Then we explore affect of photocatalytic properties with the weight ratio of FMO/C to TiO2 changed. The results showed that the porous nanostructures and photoresponse range of the composite nanofibers can be controlled by varying the proportion of both template and titanium source. The resultant composite nanofibers exhibited highly efficient removal of dye from wastewater by combining adsorption and photocatalysis processes. In addition, the composite nanofibers are superparamagnetic, and can be recovered by magnet easily with almost no decline in the removal efficiency. The facile synthesis strategy used here might provide a universal and efficient method to fabricate one-dimensional magnetic nanocomposites withporous structures for various functional applications.(2) Co/Ni@TiO2 nanofiber composite materials: A facile process for the fabrication of Co/Ni@TiO2 nanofiber composite materials has been presented in this study. The main raw materials are tetrabutyl titanate, hydrated cobalt chloride, nickel chloride hexahydrate and Nitrilotriacetic acid. And we have characterized the nanofiber composite materials by XRD, SEM, UV-Vis, DRS, Zeta potential and other methods to study the phase composition, microstructure and properties of light absorption properties of the as-prepared photocatalysts. The photocatalytic properties and optical properties of them also have been detected. Then we explore the affect of photocatalytic properties with the molar ratio of CN-NF to TiO2 changed. The results showed that the porous nanostructures and photoresponse range of the composite nanofibers can be controlled by varying the proportion of both template and titanium source. The resultant composite nanofibers exhibited better efficient removal of dye from wastewater than Pure TiO2.(3) CM@TiO2 and SiO2@TiO2 nanofiber composite materials: Facile processes for the fabrication of CM@TiO2 and SiO2@TiO2 nanofiber composite materials have been presented in this study. And we have characterized the the nanofiber composite materials by XRD, SEM, UV-Vis, DRS to comprehend the phase composition, microstructure shape appearance. We investigated the photocatalyst activity of each materials samples under simulated light irradiation with the Congo Red and methyl orange as the simulated pollution to photocatalytic degradation, in order to explore the impact about CM@TiO2 samples photocatalytic properties of mass percentage of CM-NF. The results showed that the porous nanostructures and photoresponse range of the composite nanofibers can be controlled by varying the proportion of both template and titanium source. The resultant composite nanofibers(CM@TiO2 and SiO2@TiO2) exhibited better efficient removal of dye from wastewater than Pure TiO2.