金属有机骨架复合催化剂的制备及光催化性能研究

发布时间：2018-10-15 13:00

【摘要】：染料废水因高溶解性和稳定性,在治理方面十分棘手。为应对日益严重的染料废水污染,现阶段急需研究一种全面有效的治理染料废水的新型材料或技术。金属有机骨架(MOFs)作为近年来发展迅猛的一类重要的新型多孔材料,因制备方式多样,配体及中间金属离子可控,使得金属有机骨架在众多研究方向拥有广泛的利用前景,MIL-100(Fe)作为一种常见易合成MOFs,将其应用于催化方向引起了材料科研工作者的广泛关注。本文以制备MIL-100(Fe)复合光催化剂为研究重心,通过选择合适的方法,合成了窄带氮化碳CNFs/MIL-100(Fe)和炭气凝胶CA/MIL-100(Fe)复合光催化剂,有效地提高了光诱导电子空穴对的分离效率,获得了高效可见光驱动复合光催化剂。取得具体成果如下:1.为寻找一种周期较短,操作简单且成本低,并能具有良好的光降解染料能力的金属有机骨架MIL-100(Fe),分别用sol-gel(溶胶-凝胶法),水浴法,高压水热法制备了三种MIL-100(Fe)。通过对制备催化剂样品的表征研究各项性能。相比之下,三种金属有机骨架表面积大,传统的孔隙材料不能与之相比。采用水浴法制备的金属有机骨架催化剂,比表面大,孔隙多,经其他材料修饰后则是一种较为理想的光催化材料,其降解染料的成本会大大降低,所以将水浴法作为制备复合金属有机骨架催化剂的研究重点。2.以水浴法合成的MIL-100(Fe)为载体,进一步研制CNFs/MIL-100(Fe)金属有机骨架复合光催化剂。用各种表征手段研究了复合催化剂的微观构造和表面形貌。并对制备的CNFs/MIL-100(Fe)复合金属有机骨架在可见光下对罗丹明B进行降解测试,探究CNFs/MIL-100(Fe)可见光下降解罗丹明B的反应机理。经过实验结果表明,CNFs/MIL-100(Fe)复合金属有机骨架光催化剂相比纯的MIL-100(Fe)催化活性得到显著的提高。CNFs掺杂量的变化对MIL-100(Fe)复合金属有机骨架光催化剂的影响得到系统的研究,并得到当掺杂量为1.5wt%的MIL/CNFs复合金属有机骨架光催化剂的活性达最大值,96%的RhB在可见光下被降解,并且具备较好的稳定性,这归因于CNFs和MIL-100(Fe)之间的协同作用:伴随CNFs的引入,提高了光生电子空穴对的分离效率,降低了电子空穴对的复合率,同时催化剂的光腐蚀性也会下降。所以,所制备的CNFs/MIL-100(Fe)复合催化剂对染料降解有较大的应用前景。3.通过生物质碳基气凝胶(CA)与金属有机骨架MIL-100(Fe)结合,两者之间的协同效应加强MIL-100(Fe)在吸附与光催化的性能。利用XRD、FT-IR、SEM、EDS等手段对纳米粒子的理化性质和光催化性能进行研究。经分析,CA/MIL-100(Fe)表现出优异的光吸收性能,其中CA/MIL-100(Fe)-0.5wt%具备比单体更大的吸附性能和光催化性能,其对RhB染料的降解能达到97%。该复合催化剂以生物质碳基气凝胶为原料,成本低,耐腐蚀,是一种节能减排的新材料。
[Abstract]:Dye wastewater is very difficult to treat because of its high solubility and stability. In order to deal with the increasingly serious pollution of dyestuff wastewater, it is urgent to study a new material or technology for the treatment of dyestuff wastewater. Organometallic skeleton (MOFs) is an important new porous material which has been developed rapidly in recent years. Because of its various preparation methods, the ligand and intermediate metal ions can be controlled. Organometallic frameworks are widely used in many research fields. MIL-100 (Fe), as a common synthetic MOFs, has attracted wide attention of material researchers. In this paper, the synthesis of narrow band carbon nitride (CNFs/MIL-100 (Fe) and carbon aerogel (CA/MIL-100 (Fe) composite photocatalysts was carried out by choosing suitable methods to prepare MIL-100 (Fe) composite photocatalysts. The separation efficiency of photoinduced electron hole pairs was improved effectively. High efficient visible light driven composite photocatalyst was obtained. Concrete results are as follows: 1. In order to find a metal-organic skeleton MIL-100 (Fe), with short cycle, simple operation, low cost and good photodegradation ability, three kinds of MIL-100 (Fe). Were prepared by sol-gel (sol-gel method), water-bath method and high-pressure hydrothermal method, respectively. The properties of the prepared catalyst samples were studied. In contrast, the surface area of the three organometallic frameworks is large, and traditional porous materials cannot be compared with them. The organometallic skeleton catalyst prepared by water bath method is a kind of ideal photocatalytic material after modification with other materials, and the cost of degradation of dyes will be greatly reduced. Therefore, the water bath method as the preparation of composite metal and organic framework catalyst focus. 2. The CNFs/MIL-100 (Fe) metal-organic skeleton composite photocatalyst was further developed using MIL-100 (Fe) synthesized by water bath method as the carrier. The microstructure and surface morphology of the composite catalyst were studied by various characterization methods. The degradation of Rhodamine B by CNFs/MIL-100 (Fe) composite organometallic skeleton was studied under visible light, and the mechanism of CNFs/MIL-100 (Fe) degradation of Rhodamine B was investigated. The experimental results show that the catalytic activity of CNFs/MIL-100 (Fe) composite organometallic skeleton photocatalyst is significantly higher than that of pure MIL-100 (Fe). The effect of CNFs doping on MIL-100 (Fe) composite organometallic skeleton photocatalyst is systematically studied. The results showed that the activity of MIL/CNFs composite metal-organic skeleton photocatalyst with 1.5 wt% doping reached the maximum, 96% of RhB was degraded under visible light and had good stability, which was attributed to the synergism between CNFs and MIL-100 (Fe): with the introduction of CNFs, The separation efficiency of photogenerated electron hole pair was improved, the recombination rate of electron hole pair was decreased, and the photocorrosion of the catalyst was also decreased. Therefore, the prepared CNFs/MIL-100 (Fe) composite catalyst has a great application prospect in dye degradation. 3. The synergistic effect between biomass carbon-based aerogel (CA) and organometallic skeleton (MIL-100 (Fe) enhanced the adsorption and photocatalytic properties of MIL-100 (Fe). The physicochemical properties and photocatalytic properties of nanoparticles were studied by means of XRD,FT-IR,SEM,EDS. The results show that CA/MIL-100 (Fe) exhibits excellent photoabsorption, and CA/MIL-100 (Fe)-0.5 wt% has better adsorption and photocatalytic properties than monomer, and its degradation of RhB dyes can reach 97%. The composite catalyst is a new material for energy saving and emission reduction because of its low cost and corrosion resistance.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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