Electrospinning Preparation And Photocatalytic Properties Of Zinc Oxide And Its Composite Nanomaterials

In this paper, ZnO, Mn TiO₃, Zn O/Ag nanofibers were preparated by using the self-made electrospinning apparatus with Zn?NO₃?₂, AgNO₃, DMF, PVP, MnCl2,tetrabutyl titanate, citric acid, Ethanol and ethylene glycol as raw materials. And then combining hydrothermal method produced Zn O, Mn TiO₃/ZnO composite nanofibers with brush structure using the Zn O, Mn TiO₃ nanofibers, Zn?NO₃?₂, hexamethylenetetramine as raw materials. The influences of conditions of electrospinning, calcination and hydrothermal on the morphology and photocatalytic of the prepared samples were investigated. The phase, component and morphology of the prepared samples were characterized by XRD, TEM, SEM, PL and UV-vis. The main research content is as follows:?1? ZnO nanofibers were preparated by using electrospinning apparatus with Zn?NO₃?₂?DMF?PVP as raw materials. The influences of PVP content, spinning voltage and calcination temperature on spinnability, morphology and photocatalytic activity of the prepared samples were investigated systematically. The results as follows: when the content of PVP was 0.093 g/mL, the spinning voltage was 32 kV and calcination was 550 oC,ZnO nanofibers with good morphology and photocatalytic activity can be prepared.And then combining hydrothermal method produced ZnO nanofibers with brush structure using the Zn O nanofibers ?Zn?NO₃?₂ ?hexamethylenetetramine as raw materials. The influences of reaction time and solution concentration on morphology and photocatalytic activity of the prepared samples were investigated systematically. The results as follows:when reaction time was 4 h and solution concentration was 0.025 M, ZnO nanofibers with good brush structure and photocatalytic activity can be prepared.After irradiation for 25 min, the degradation rate of MO solution can reach 98.9%.The photocatalytic activity of Zn O nanofibers with brush structure were significantly improved compared with ZnO nanofibers.?2? Mn TiO₃ nanofibers were preparated by using electrospinning apparatus with DMF, PVP, MnCl2, tetrabutyl titanate, citric acid, Ethanol and ethylene glycol as raw materials. On this basis, combining hydrothermal method produced Mn TiO₃/ZnO composite nanofibers with brush structure using the MnTiO₃ nanofibers, Zn?NO₃?₂,hexamethylenetetramine as raw materials. The influences of the calcination temperature and holding time of Mn TiO₃ nanofibers and reaction time and solution concentration of MnTiO₃/ZnO composite nanofibers on photocatalytic activity of MnTiO₃/ZnO composite nanofibers were investigated systematically. The results as follows: when the calcination temperature and holding time of MnTiO₃ nanofibers were 900 oC and 6h, respectively and reaction time and solution concentration of MnTiO₃/ZnO composite nanofibers were 4h and 0.035 M, MnTiO₃/ZnO composite nanofibers with good brush structure and photocatalytic activity can be prepared. After irradiation for 20 min, the degradation rate of MO solution can reach 99.6%.?3? ZnO/Ag nanofibers were preparated by using electrospinning apparatus with Zn?NO₃?₂, Ag NO₃, DMF, PVP as raw materials. The influences of the calcination temperature, holding time and Ag content on photocatalytic activity of ZnO/Ag nanofibers were investigated systematically. The results as follows: when the calcination temperature and holding time of ZnO/Ag nanofibers were 550 oC and 4 h, respectively and the content of Ag was 18%, ZnO/Ag nanofibers with diameter of 150 nm, composed by particles with size of 10-30 nm can be prepared. The nanofiber has a large aspect ratio and uniform morphology. And ZnO and Ag are evenly distribted in the nanofiber forming a multi-surface contact structure. Under UV light and simulated sunlight, the Ag content of ZnO/Ag nanofibers was 18% and 15%, respectively, with the most excellent photocatalytic activity. Under UV light and simulated sunlight irradiation of 10 min and40min, the degradation rate of MO was 100% and 92%, respectively.Compared with the pure ZnO nanofibers, the photocatalytic activity was obviously improved.