摘要由于传统的光催化材料只能对占太阳光5%的紫外光产生响应,为了提高对太阳能的利用率,近年来,人们开始尝试开发新型的可见光响应光催化材料。作为一种典型的稀土钒酸盐材料,钒酸铈基材料由于其独特的光、电和氧化还原特性而得到了广泛的应用。同时,我们发现CeVO4的禁带宽度约为2.7 ev左右,是一种优良的具有可见光响应的光催化材料。
本论文以Ce(NO3)3•6H2O和Na3VO4为原料,采用水热法合成纳米光催化材料CeVO4,并研究不同pH值和表面活性剂对实验的影响,以得到高性能的CeVO4纳米粉体。将样品经XRD、SEM和紫外-可见光吸收光谱等技术进行表征,从而了解样品的结构、微观形貌及光学特性等。通过在可见光照射下(λ> 400 nm)亚甲基蓝的降解实验来评价所合成纳米CeVO4 的可见光响应光催化性能。
关键词 CeVO4 可见光响应 水热合成法 光催化 22366
毕业设计说明书(论文)外文摘要
Title Synthesis and characterization of CeVO4 as
visible-light-response photo-catalytic material
Abstract
It is known to us all that, compared to visible light (43%), ultraviolet light accounts for only a small fraction (4%) of the solar energy. However, the traditional photo-catalytic materials can just be induced by ultraviolet light. Recently, in order to enhance the absorption in the visible spectral range, it is very necessary to develop new photo-catalytic materials with visible light response. As a typical rare-earth vanadate material, cerium-vanadate-based material has been widely used because of its unique optical, electric and redox properties. Meanwhile, it is found that the band gap of CeVO4 is about 2.7eV. As a result, it is also a potential photo-catalytic material respond to visible light.
In this paper, the nano-sized photocatalysis material CeVO4 has been synthesized by hydrothermal method, in which Ce(NO3)3•6H2O and Na3VO4 are used as reactants. The effects of pH Value and surfactants have been studied in order to obtain high-quality CeVO4 nanopowders. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis absorption spectroscopy. The photocatalytic properties are estimated by the degradation of methylene blue (MB) under visible light irradiation.
Keywords CeVO4 visible light response hydrothermal synthesis method Photo-catalytic
目 次
1 绪论 1
1.1 纳米材料概述 1
1.2 纳米光催化材料简介 2
1.3 纳米光催化材料的应用 2
2 CeVO4材料 4
2.1 CeVO4材料概述 4
2.2 CeVO4材料的结构特点 4
2.3 CeVO4材料的常用合成方法 6
2.4 纳米半导体光催化剂的主要表征手段 7
2.5 CeVO4纳米颗粒的光催化 8
3 实验部分-水热法合成CeVO4纳米粉体 10
3.1 实验试剂和仪器 10
3.2 样品制备 10
3.3 样品表征 12
结 论 24
致 谢 25
参考文献26
1 绪论
1.1 纳米材料概述
20世纪80年代,纳米晶体材料这一概念由德国科学家Gleiter提出[1]。纳米材料是指晶粒尺寸为纳米级(10-9m)、结构有所改变而具有特异性能的新材料,纳米材料的典型特点就是在材料的三文空间尺寸中,必须有一文是在纳米尺寸范围(1-100nm)内的。纳米材料可以分为[2]:三文空间尺寸均为纳米级别的零文纳米材料,例如纳米粉体;三文空间尺寸中有两文为纳米级别的一文纳米材料,例如纳米线和纳米管;而三文空间尺寸中只有一文处于纳米级别的称为二文纳米材料,例如纳米薄膜和纳米片。纳米材料具备许多特殊效应[3],如表面效应、宏观量子隧道效应、量子尺寸效应、小尺寸效应(又称体积效应)、库仑阻塞效应等,这些效应在纳米材料中的综合作用,使得纳米材料呈现出奇异的力学、电学、光学、热学、化学活性、催化和超导特性等[4-6]。 可见光响应型CeVO4光催化材料的合成及其性能研究:http://www.youerw.com/cailiao/lunwen_14973.html