钽酸盐光催化剂的制备及改性研究

发布时间：2018-08-27 13:12

【摘要】：本文采用了水(溶剂)热法等多种方法分别制备了非金属离子掺杂钽酸钠与钽酸钾光催化剂。运用多种材料测试手段,例如X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、高分辨透射电镜(HRTEM)、选区电子衍射(SAED)、X射线光电子能谱(XPS)等对样品的组成、形貌、以及表面原子状态进行分析。最后对制备的钽酸钠、钽酸钾进行光催化性能评价,并利用紫外可见分光光度计测试对其吸光度性能进行表征。(1)利用TaCl5为钽源,Na2S2O3·5H2O为硫源,采用水热法一步制备了硫掺杂钽酸钠。SEM及TEM结果表明样品的粒径分布在200 nm至1μm,呈立方体结构。结果表明在140℃下并不能生成钽酸钠,在180℃下可以生成晶型较好的钽酸钠。XPS结果显示,钽酸钠晶格中掺杂的硫离子代替了原来晶格中的氧离子,使钽酸钠的禁带宽度减小,光响应范围延伸至可见光,吸收带边发生了红移。光催化测试表明硫掺杂钽酸钠在可见光下对罗丹明B有着较好的催化降解效果。(2)以TaCl5为钽源,以水和乙二醇的混合溶液为溶剂,采用溶剂热法制备了碳掺杂钽酸钠。SEM结果显示,样品为立方体,粒径约为1μm,样品的分散性较差。XRD结果表明,反应物钽酸钠样品的晶相为钙钛矿结构的NaTaO3。并且溶剂中乙二醇比例越高,结晶性越差。光催化测试表明,溶剂中水与乙二醇的最佳比例为10:20。(3)利用了两步水热法合成了氮掺杂钽酸钾。先在NH3气氛中烧结制备N-Ta2O5前驱体,再利用水热法制备K2Ta2O6。XRD结果显示样品晶相为K2Ta2O6。SEM结果显示,K2Ta2O6样品的粒径尺寸大约为100 nm。当反应时间延长,样品的表面形貌由颗粒逐渐生长为正八面体最终生长为立方体结构。光催化测试结果表明,反应时间为24 h,反应温度在180℃时获得的钽酸钾的光催化性能最佳。
[Abstract]:In this paper, non-metallic ion doped sodium tantalate and potassium tantalate photocatalysts were prepared by hydrothermal method. The composition and morphology of the samples were investigated by means of X-ray diffractometer, (XRD), scanning electron microscope, (SEM), transmission electron microscope, (TEM), high resolution transmission electron microscope, (HRTEM), selective electron diffraction, (SAED) X-ray photoelectron spectroscopy (XPS), X-ray photoelectron spectroscopy (XPS), etc. And surface atomic states are analyzed. Finally, the photocatalytic properties of sodium tantalate and potassium tantalate were evaluated, and their absorbance was characterized by UV-Vis spectrophotometer. (1) TaCl5 was used as tantalum source and Na _ 2S _ 2O _ 3 5H2O as sulfur source. Sulfur doped sodium tantalate was prepared by hydrothermal method. The results of SEM and TEM showed that the particle size distribution of the sample ranged from 200 nm to 1 渭 m, with cubic structure. The results show that sodium tantalate can not be formed at 140 鈩，

本文编号：2207397