Study On The Preparation And Properties Of Electrospun Inorganic Nanofibers

One-dimensional nano materials, which have desirable structure and functionalities, have been a subject of recent investigation due to their potential importance. Variety kinds of organic and/or inorganic nanofibers, nanobelts and nanowires have been synthesized and applied. Elelctrospinning technique is a simple and versatile method to prepare continuous ultrafine nanofibers with diameters down to micro and nano scale. Variety kinds of inorganic nanofibers can be prepared by adjusting the ingredient of the spinning solution. The hierarchical nanofibers have high surface area, which have been applied in university laboratories and industry. The nanofibers can be applied in catalysis, sensors, optical devices, filtration and biomedical application.In this paper, inorganic nanofibers were synthesized by sol-gel processing and electrospinning technique, including silica and titania nanofibers. We systematically investigated the parameters which effected the structure of the nanofibers. We also investigated the adsorption property and the photoelectric property of the nanofibers. The results as followed(1) Preparation of silica nanofibers: TEOS and Polystyrene(PS) were added to the PVP solution to prepare spinning solution. PS nanoparticals were incorporated into the silica/PS/PVP nanofibers as the pore-precursors. Hierarchical porous nanofibers with micro-and mesopores were conveniently obtained via the calcination method. We found that the porosity and pore size of the prepared nanofibers increased with the particle concentration of the spinning solution increased under a fixed feeding rate, applied distance and collecting distance.(2) Study on the adsorption performance of the silica nanofibers. Silica nanofibers were soaked in the Rhodamine B solution. After certain soaking time, optical absorption spectra of the solutions were measured to characterize the dye adsorption performance of prepared silica nanofibers. The dye absorption ability was increased with the quantity and volume of the mesopores on the surface of silica nanofibers increased.(3) Preparation titania nanofibers: Tetraisopropyl Orthotitanate(C12H28O4Ti) was added to PVP solution for electrospinning titannia/PVP nanofibers. Hierarchical porous titania nanofibers were conveniently obtained via the calcination method. It indicated that titania inorganic nanofibers with different diameters and pore sizes have been obtained by simply adjusting the parameters of the spinning process and the calcination temperature.(4) Study on the photoelectric performance of the titania nanofibers. The PVP/titania nanofibers membranes prepared by electrospinning method were cut-stacked-cut to get thin membranes, which was transferred on the conducting glass after calcination. The titania nanofibers was used as photoanode of the dye-sensitized solar cells(DSSC). The influences of the orientation of prepared nanofibers membranes on the solar-to-current conversion efficiency were investigated. The results indicate that when standing titania membranes as photoanodes in DSSC, the solar-to-current conversion efficiency was 3.76%, which was higher than the lying titania membranes.