摘要二氧化钛(TiO2)是一种光催化性能很高的材料,能够利用光能将有机污染物降解,但是在实际应用中,其对太阳光利用率低、分离回收困难等因素,也限制了TiO2的应用领域。为了提高TiO2的综合光催化性能,本课题利用共轭静电纺丝技术制备了TiO2/C复合材料,大大降低了分离回收的难度,同时提高了光催化催化效率。25840
本课题第一部分探究TiO2聚合物纤文的静电纺丝最佳条件和烧结工艺:以钛酸异丙酯(Ti(OiPr)4)、聚乙烯吡咯烷酮(PVP)和聚丙烯腈(PAN)为主要原料,采用单针头静电纺丝技术(改变电纺条件)并辅以不同的热处理过程,分别制备出不同尺寸的TiO2纤文,使用显微镜观察电纺纤文形貌分别确定适应的电纺条件。TiO2纤文最佳静电纺丝条件:钛酸异丙酯(K90)浓度C=12 wt%,纺丝电场强度=1.0×105 V•m-1,纺丝速率=0.8 mL•h-1。探究热处理适宜条件:通过XRD、TG、FTIR等分析方法研究TiO2的晶型转变和纺丝纤文组分变化,焙烧温度从500℃到900℃的过程中,TiO2由锐钛矿型向金红石型转变。
本课题第二部分探究TiO2/C二元并列纤文膜的在一系列热处理过程中形貌和组分结构的变化以及光催化性能和力学强度。采用共轭电纺技术制备TiO2/C二元并列纤文膜,SEM和TEM照片有力地证明该制备方法可以有效地制备TiO2/C二元并列纤文膜,纤文并列成功率最高,原丝直径分布在400—500纳米,且纺丝连续。罗丹明(RhB)和硝基苯(NB)光催化降解实验表明,TiO2/C二元并列纤文膜可以有效降解水溶性和油溶性污染物。接触角实验表明,TiO2/C二元并列纤文膜具有良好双亲性。XRD测试结果表明,700℃时TiO2以混合晶型存在于纺丝纤文中对RhB降解效果最佳,纺丝类型对RhB降解影响不大;500℃时锐钛矿型的TiO2/C并列纤文在降解NB时具有较好的催化性能。微流动场光催化试验证明,TiO2/C并列纤文具有良好的力学性能。
关键词 TiO2 光催化 纳米复合纤文 PAN碳纤文 共轭纺丝 二元并列纤文
毕业论文设计说明书外文摘要
Title Preparation and catalytic properties of photocatalytic composite fiber membranes
Abstract
Titanium dioxide (TiO2) is a kind of high photocatalytic materials, it can use light to degrade organic pollutants. However, in practice, the low utilization of sunlight, separation and recovery of difficulty and other factors also limit the applications of TiO2. In order to improve the photocatalytic activity of TiO2, We use the conjugate electrospinning to prepare the TiO2/C composites, greatly reduces the difficulty of separation and recovery, and improving the photocatalytic activity.
The first part of this paper is to explore the TiO2 nanofibers’ optimum conditions of electrospinning and sintering processes. Ti(OiPr)4 、PVP and PAN are used as the main raw material, using the single needle electrospinning technique (chaning the electro-spinning conditions) and complemented by different heat treatment process, and preparing different sizes of TiO2 fibers. The electrospun fiber morphology’s microscope are determined to adapt the electrical discharge conditions. TiO2 nanofibers’ optimum spinning conditions: isopropyl titanate (Ti(OiPr)4) concentration C = 12 wt%, spinning electric field strength = 1.0 × 105V • m-1, the spinning rate = 0.8 mL•h-1. Exploring suitable heat treatment conditions: study the phase transformation of TiO2 and spun fiber composition changes by analysis of XRD, TG, FTIR, TiO2 from anatase to rutile transition as the process of calcination temperature from 500 ℃ to 900 ℃.
The second part of this paper is to explore the TiO2/C binary parallel fiber membrane’s changes of morphology and structure ,photocatalytic activity and mechanical strength in a series of heat treatment. TiO2/C binary parallel fiber membrane is prepared by conjugate electric spinning, SEM and TEM’s photographs are strong evidences that the preparation method can be efficiently prepared TiO2/ C binary parallel fiber membrane, the nanofibers are tied for the highest success rate, strand diameter distribution 400-500 nm, and continuous spinning. Rhodamine (RhB) and nitrobenzene (NB) photocatalytic degradation experiments show, TiO2 / C binary parallel fiber membrane can effectively degrade water-soluble and oil-soluble pollutants. The contact angle experiments’ results show that TiO2/ C binary parallel fiber membrane has a good amphiphilicity. XRD results show that the mixed crstal forms in 700℃ of TiO2 degradate RhB best, types of fibers have a little effect on the degradation of RhB. TiO2 in the anatase form at 500℃ has a better catalytic performance in degradating NB. Micro flow field photocatalytic tests proved, TiO2/ C parallel fiber has good mechanical properties. 光催化复合纤维膜的制备及催化性能:http://www.youerw.com/huaxue/lunwen_19804.html