摘要全 氟 辛 酸 (perfluorooctane acid , PFOA) 是 广 泛 存 在于 水 体 中 的 典 型 全 氟 化 合 物 (perfluorinated compounds,PFCs)。强碳氟共价键(C-F)的存在,使 PFOA 具有极强的热稳 定性和化学稳定性,光照、加热、氧化还原、微生物等作用均无法使其降解。光催化法是 一种反应条件温和、操作简单、无二次污染的 PFOA 高效去除技术。本课题以制备的载铂 氧化铟纳米棒(a%Pt/IONRs-b,a 表示铂负载量,b 表示焙烧温度)作为光催化降解水体中 PFOA 的光催化剂。采用 X 射线衍射(XRD)、X 射线光电子能谱(XPS)、透射电子显微镜 (TEM)、N2 吸附-脱附、紫外-可见光谱分析(UV-VIS)等分析方法,对载铂氧化铟纳米棒的 形貌、结构及化学组成等进行了表征。最后考察了载铂氧化铟纳米棒光催化降解 PFOA 过 程的影响因素。主要得出如下结论:
以介孔二氧化硅(SBA-15)为模板、硝酸铟为前驱体,在焙烧温度为 300℃、500℃、700℃ 和 900℃ 的 条 件 下 , 制 备 出 了 一 系 列 具 有 高 度 有 序 结 构 的 载 铂 氧 化 铟 纳 米 棒 (3%Pt/IONRs-b),并且伴随焙烧温度的升高材料中铟元素含量不断降低。光催化实验结果 显示材料焙烧温度对载铂氧化铟纳米棒光催化降解 PFOA 的效率有一定影响:IONRs-700> IONRs-500>IONRs-900> IONRs-300;其次,共存离子对载铂氧化铟纳米棒光催化降解 PFOA 的效率有不同程度影响:硫酸根离子对反应有显著抑制作用,而氯离子和溴离子的 加入对反应几乎不产生影响;最后,溶液 pH 对载铂氧化铟纳米棒光催化降解 PFOA 的效 率有显著影响:3%Pt/IONRs-700 对 PFOA 的光催化降解效果随 pH 值升高而降低,在 pH 值为 9。27 时降解率仅为 5%,而在 pH 值为 1。85 时降解率可高达 98%。76148
毕业论文关键词 全氟辛酸 光催化 载铂氧化铟纳米棒
毕 业 设 计 说 明 书 外 文 摘 要
Title Preparation of Platinized Indium Oxide Nanorods and Photocatalytic Decomposition for Perfluorooctane Acid in the Wastewater
Abstract Perfluorooctane acid (PFOA) with high-energy carbonefluorine (C-F) bonds are representative perfluorinated octane compounds in the wastewater。 Because of its exceptionally high stability, PFOA are difficult to decompose by heat, light, oxidation-reduction and biological degradation。 Photocatalytic decomposition is an effective and economical method to remove
PFOA from wastewater。 Platinized indium oxide nanorods (a%Pt/IONRs-b,a is Platinum load,
b is the calcination temperatures ) were successfully prepared。 The overall appearance, internal structure, chemical composition and magnetic properties of platinized indium oxide nanorods were evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), N2 adsorption-desorption analysis and Ultraviolet-visible spectrum (UV-VIS) analysis。 The behaviors of photocatalytic decomposition perfluorooctanoic acid (PFOA) with platinized indium oxide nanorods were studied。 The main conclusions can be summarized as follows:
In the calcination temperature at 300℃, 500℃, 700℃ and 900℃, the highly ordered
mesoporous structure of platinized indium oxide nanorods were successfully synthesized, and the average pore diameter was about 4。2 nm。 Indium (In) content of platinized indium oxide nanorods decreased with increasing the calcination temperatures。 Results showed that the photocatalytic decomposition capacities of platinized indium oxide nanorods for PFOA was affected the calcination temperatures partly。 3%Pt/IONRs-700>IONRs-700 > IONRs-500 > IONRs-900 > IONRs-300。 Moreover, co-existing ions affects the photocatalytic decomposition capacities of platinized indium oxide nanorods for PFOA differently。 Chloridion and bromide ion hardly affect the photocatalytic decomposition capacities, but sulfate ion has