二氧化钛纤维为基体的光催化剂的制备及其性能研究

发布时间：2018-11-13 10:25

【摘要】：如今,随着生产效率和生活节奏的不断加大,周边环境污染问题日益突出。环境污染问题若不能得到大家的关注,伴随而来的大气污染,水体污染,陆地污染,会造成温室效应,生态平衡和对人体健康产生危害。为了追求更好的生活环境,开发更优异的光催化剂显得很有意义。在众多半导体光催化材料中,TiO_2因为高稳定性、无毒、无二次污染和低成本等优点,在污染物处理和光能转换等方面拥有很大的应用价值。目前,TiO_2是应用最多的催化剂。但是,TiO_2较宽的带隙,只能吸收利用波长λ387.5 nm的光,太阳光利用率低和光生电子与空穴容易复合等缺点极大地限制了该类催化剂的进一步推广。研究发现进行掺杂,负载后的二氧化钛,其应用范围会更广。因此,本论文设计选择TiO_2纤维作为载体制备出Bi、V共掺的TiO_2纤维和MoS_2/CdS/TiO_2纤维材料。该材料具有可见光催化性质、同时提高了光催化剂在污水的回收利用率。论文主要包括以下内容:(1)以钛酸正丁酯,乙酰丙酮,PVP,无水乙醇为原料,制得前驱体凝胶,后经过静电纺丝技术,热处理得到二氧化钛纤维。该纤维为锐钛矿相的二氧化钛,纤维的直径在300到400纳米,长度大于1微米,表面有平行于长度方向的沟壑。(2)将钒酸盐与硝酸铋溶解在一定浓度的硝酸中作为掺杂液,混入(1)中的前驱体凝胶中,后经过静电纺丝技术,热处理得到Bi、V共掺的TiO_2纤维。取20mg的催化剂对50m L的5mg/L的Rh B进行可见光降解,发现(Bi+V)/Ti的摩尔数之比为27.3%的Bi、V共掺TiO_2纤维,与未掺杂TiO_2纤维相比,可见光催化性质有较大提升。(3)将TiO_2纤维作为载体,通过两次水热法,先水热负载硫化镉后,再次通过水热法负载二硫化钼,得到三元复合材料MoS_2/CdS/TiO_2,并对其进行了一系列的表征(XRD,SEM,TEM)和测试。发现该催化剂的组成为,TiO_2纤维为载体,表面负载颗粒状的硫化镉和极细层状的二硫化钼。取20mg的催化剂对50m L的15mg/L的MB进行可见光降解,发现该催化剂的吸附性质明显,同时3小时内可见光降解率接近80%。
[Abstract]:Nowadays, with the increasing of production efficiency and living rhythm, the problem of environmental pollution is becoming more and more serious. If the environmental pollution problem can not get everybody's attention, the accompanying air pollution, water pollution, land pollution will cause Greenhouse Effect, ecological balance and harm to human health. In order to pursue a better living environment, it is meaningful to develop better photocatalyst. Among many semiconductor photocatalytic materials, TiO_2 has great application value in pollutant treatment and photoenergy conversion because of its advantages of high stability, non-toxicity, no secondary pollution and low cost. At present, TiO_2 is the most widely used catalyst. However, the wide band gap of TiO_2 can only absorb the light with wavelength 位 387.5 nm. The low utilization of solar light and the easy recombination of photogenerated electrons and holes greatly limit the further popularization of this kind of catalyst. It is found that the doped and loaded titanium dioxide will be more widely used. Therefore, Bi,V co-doped TiO_2 fiber and MoS_2/CdS/TiO_2 fiber were prepared by using TiO_2 fiber as carrier. The material has the properties of visible light catalysis and improves the recovery efficiency of the photocatalyst in wastewater. The main contents of this paper are as follows: (1) the precursor gel was prepared by using n-butyl titanate acetylacetone and PVP, anhydrous ethanol as raw materials. The fiber is anatase phase titanium dioxide, the diameter of the fiber is 300 to 400 nanometers, the length is more than 1 micron, the surface has a ravine parallel to the length direction. (2) vanadate and bismuth nitrate are dissolved in a certain concentration of nitric acid as the doping solution. Bi,V co-doped TiO_2 fibers were prepared by electrospinning after mixing with the precursor gel in (1). The Rh B of 50 mL 5mg/L was degraded by visible light using the catalyst of 20mg. It was found that the mole ratio of (Bi V) / Ti was 27.3% Bi,V co-doped TiO_2 fiber, which was compared with undoped TiO_2 fiber. (3) the TiO_2 fiber was used as the carrier. (3) the ternary composite MoS_2/CdS/TiO_2, was obtained by using the TiO_2 fiber as the carrier, the cadmium sulfide was first hydrothermal supported, and then the molybdenum disulfide was then supported by the hydrothermal method. A series of characterization (XRD,SEM,TEM) and tests were carried out. It was found that the catalyst was supported by TiO_2 fiber and supported on the surface of granular cadmium sulfide and very fine layer molybdenum disulfide. The MB of 50 mL 15mg/L was degraded by visible light using 20mg catalyst. It was found that the adsorption property of the catalyst was obvious, and the visible light degradation rate was close to 80% within 3 hours.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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