中空双壳层CdS@ZnS纳米复合材料的制备及其性能研究

发布时间：2019-03-11 19:32

【摘要】：核壳型复合材料因可以通过改变核、壳的组分及配比对其整体性能进行修饰、改性,而在催化技术中得到广泛的研究,其中以CdS为基材的核壳纳米复合材料是近年来广受关注的一类新型材料。但是CdS在光照下易发生“光腐蚀”,不仅造成Cd2+的水体污染,同时降低材料的催化活性。针对上述问题,论文欲建构具备中空、双壳层结构的CdS@ZnS复合光催化剂。本论文首先采用乳液聚合法制备单分散的聚苯乙烯微球(PS),以醋酸镉、硫代乙酰胺为前驱体,聚乙烯吡咯烷酮(PVP)作为稳定剂与分散剂,通过不同方法获得PS@CdS核壳纳米复合材料。在得到PS@CdS核壳纳米复合材料后,制备PS@CdS@ZnS双壳层纳米复合材料,分别探讨不同实验方法、不同前驱体以及不同PVP用量对实验的影响,得出最佳实验条件。采用甲苯刻蚀、高温煅烧的手段除去中心模板得到中空CdS纳米材料及中空双壳层CdS@ZnS纳米复合材料。通过SEM、TEM、EDS、FT-IR、XRD和UV-vis等测试手段分析样品的微观形貌、元素组成、分子结构及吸光性能。结果表明:实验制备的材料具有明显的中空、双壳层结构,粒径可控,单分散性良好,机械强度较高,内壳层厚度为80~100 nm,外壳层厚度约为40 nm。最后,通过废水模拟实验表明,0.2 g·L-1的中空双壳层CdS@ZnS复合光催化剂降解300 mL,10 mg·L-1的RhB溶液,光照160 min的降解率为99.7%。同时,该催化剂在五次循环利用后的降解率仍保持在98%左右,稳定性较好,从而降低Cd2+的水体污染,表明在处理印染废水中的巨大潜力。
[Abstract]:Core-shell composites have been extensively studied in catalytic technology because they can be modified and modified by changing the composition and proportion of core and shell. Core-shell nanocomposites based on CdS are a new kind of materials which have been paid more and more attention in recent years. However, CdS is prone to "photocorrosion" under light, which not only causes the water pollution of Cd2, but also decreases the catalytic activity of the material. In order to solve these problems, the CdS@ZnS composite photocatalyst with hollow and double shell structure was constructed in this paper. In this paper, monodisperse polystyrene microspheres (PS),) were prepared by emulsion polymerization method, using cadmium acetate, thioacetamide as precursor, polyvinyl pyrrolidone (PVP) as stabilizer and dispersant, and polyvinylpyrrolidone (PVP) as stabilizer and dispersant. PS@CdS core-shell nanocomposites were obtained by different methods. After the PS@CdS core-shell nanocomposites were obtained, the PS@CdS@ZnS double-shell nanocomposites were prepared. The effects of different experimental methods, different precursors and different PVP content on the experiment were discussed, and the optimum experimental conditions were obtained. Hollow CdS nano-materials and hollow double-shell CdS@ZnS nanocomposites were prepared by toluene etching and high temperature calcination. The microstructure, element composition, molecular structure and absorptivity of the samples were analyzed by SEM,TEM,EDS,FT-IR,XRD and UV-vis. The results show that the prepared materials have obvious hollow, double shell structure, controllable particle size, good monodispersity, high mechanical strength, and the thickness of the inner shell is about 40 nm. the thickness of the inner shell is 80 nm, and the thickness of the outer shell is about 40 nm.. Finally, the experimental results of wastewater simulation showed that the degradation rate of RhB solution was 99.7% with 0.2 g 路L ~ (- 1) hollow double shell CdS@ZnS composite photocatalyst for 300 mL,10 mg 路L ~ (- 1) RhB solution under illumination of 160 mol 路L ~ (- 1) and 0.2 g 路L ~ (- 1). At the same time, the degradation rate of the catalyst remains about 98% after five cycles of recycling, and the stability of the catalyst is good, thus reducing the water pollution of Cd2, indicating that the catalyst has great potential in the treatment of printing and dyeing wastewater.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O643.36

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