硫化锌纳米管基材料的设计合成及其吸附性能研究

发布时间：2018-05-04 11:11

本文选题：硫化锌纳米管 + ZnS纳米管/CdS空心球复合材料　；参考：《山东大学》2017年硕士论文

【摘要】：人们发现大部分饮用水中含有多种毒素和致病微生物,它们主要来自未经处理的工业废水。因此,治理污水刻不容缓。在各种污染物中,有机染料是目前水污染的主要污染物。吸附技术凭借其灵活性及高效性成为一种很有前途的能有效去除有机染料的方法。作为吸附的核心技术,能够用来去除水中有机染料的吸附剂有很多。但是,因为染料种类颇多,一种特定的吸附剂不可能去除所有类型的染料。因此,开发一种能够既能够简易合成,又能对某些染料有高效去除效率和良好选择性的吸附剂对实际应用具有重要意义。作为一种无毒、环保材料,ZnS纳米材料在光催化降解有机染料方面用的比较多。可是用作有机染料吸附处理方面的并不多,仅有少数报道提到用硫化锌基活性炭、过渡金属掺杂的硫化锌基活性炭、硫化锌基纳米纤维等作为有机染料吸附剂。然而,并没有有人研究硫化锌纳米管在这方面的运用。众所周知,空心纳米管通常有很大的比表面积,这可能为染料分子的吸附提供更多的活性位点。因此,预测硫化锌纳米管会是一种很好的吸附剂。但是,硫化锌纳米管的制备过程大多数需要经过添加表面活性剂、高温、高压等特殊过程,这可能是导致硫化锌纳米管在吸附处理有机染料方面应用很少的主要原因。因此,研发一种合成方法简单、吸附效率高且具有良好选择性的硫化锌纳米管吸附剂对实际应用具有重要意义。基于以上研究背景,我们以硫化锌纳米管为研究对象,在其制备方法及吸附性能等方面进行了深入探索。本论文主要研究内容如下:第二章,创新性地提出了一种简单有效的合成硫化锌纳米管的方法:在室温下只使用三种原料(Zn(CH3COO)2,NaHC03和Na2S),通过两步合成路线成功合成硫化锌纳米管。整个合成路线经济环保,不需要任何煅烧步骤,没有添加任何的表面活性剂,更没有额外的模板辅助。这一产品主要用于废水中有机染料的吸附处理。吸附实验表明,其对带NH2/NH-官能团的阴离子染料显示出高效的选择性,以CR为例,其最大吸附量可高达724.6 mg g-1,高于许多文献中报道的复合材料对CR的吸附。这主要是由于硫化锌纳米管表面的硫缺陷吸附了很多水分子,使得纳米管与染料分子的NH2/NH-官能团之间存在氢键和静电吸附的协同效应。因此,本项研究提供了一种很有前景的水处理或从染料混合物中选择性分离带-NH2/-NH-基团阴离子染料的吸附剂。也为后续设计一种通过调控表面缺陷达到对某些有机染料选择性吸附的硫化锌纳米结构提供重要的线索。第三章,提出了一种室温合成ZnS纳米管/CdS空心球纳米复合材料的新方法。只使用四种低成本的原材料(Zn(CH3COO)2、Na2CO3、Cd(CH3COO)2和Na2S)。首先,通过两步直接沉淀过程,便成功合成了棒/CdCO3复合物前驱,然后通过简单的离子交换反应一步合成出目标产物ZnS纳米管/CdS空心球复合材料。整个实验过程都是在常温下进行的,对合成设备要求很低。我们将这一复合材料用做有机染料吸附剂。吸附实验表明,ZnS/CdS复合材料对带NH2/NH-的阴离子染料的选择吸附性远远高于ZnS纳米管。此外,ZnS/CdS复合材料对CR的最大吸附量可高达950 mg g-1。因此,本工作开创了一种常温直接沉淀法合成空心复合材料的新思路,对今后合成其它复合材料将会有很大的参考价值,同时也表明了空心复合材料在吸附处理有机染料方面的巨大潜力。
[Abstract]:It is found that most of the drinking water contains a variety of toxins and pathogenic microbes, which mainly come from untreated industrial wastewater. Therefore, it is urgent to treat sewage. In all kinds of pollutants, organic dyes are the main pollutants of water pollution. Adsorption technology has become a promising and effective method for its flexibility and efficiency. The method of removing organic dyes. As the core technology of adsorption, there are many adsorbents that can be used to remove organic dyes in water. However, because of the variety of dyes, a particular type of adsorbent can not remove all types of dyes. Therefore, the development of a kind of dyes can be both simple and efficient for the removal of some dyes and the efficiency of the dye removal. Good selective adsorbents are of great significance for practical applications. As a non-toxic, environmentally friendly material, ZnS nanomaterials are used in the photocatalytic degradation of organic dyes. But it is not much used as organic dye adsorption treatment. Only a few reports refer to zinc sulfide based activated carbon and transition metal doped ZnS base. Active carbon, zinc sulfide nanofibers, etc. are used as adsorbents for organic dyes. However, no one has studied the application of zinc sulfide nanotubes in this field. It is known that hollow nanotubes usually have a large specific surface area, which may provide more active sites for the adsorption of dye molecules. Therefore, it is very important to predict zinc sulfide nanotubes (ZnS nanotubes). Good adsorbents. However, most of the preparation process of zinc sulfide nanotubes requires special processes such as adding surfactants, high temperature and high pressure. This may be the main cause of the application of zinc sulfide nanotubes in the adsorption treatment of organic dyes. Therefore, the research and development of a synthetic method is simple, high adsorption efficiency and good choice. Zinc sulfide nanotube adsorbents are of great significance for practical applications. Based on the above research background, we have explored the preparation methods and adsorption properties of zinc sulfide nanotubes as the research object. The main contents of this paper are as follows: the second chapter, a simple and effective synthetic vulcanization is proposed. Zinc nanotube method: using only three kinds of raw materials (Zn (CH3COO) 2, NaHC03 and Na2S) at room temperature, zinc sulfide nanotubes are successfully synthesized through a two step synthesis route. The whole synthesis route is economical and environmental, no calcining steps are needed, no surfactants are added and no additional template assists are added. This product is mainly used in wastewater. Adsorption experiments of organic dyes. Adsorption experiments show that they show high selectivity for anionic dyes with NH2/NH- functional groups. The maximum adsorption capacity of CR is as high as 724.6 mg g-1, which is higher than that of CR, which is reported in many literature. This is mainly due to the sorption of a lot of water on the surface of the zinc sulfide nanotube. Molecular, the synergistic effect of hydrogen bonds and electrostatic adsorption between the NH2/NH- functional groups of the nanotube and the dye molecules. Therefore, this study provides a promising water treatment or selective separation of the adsorbents with the -NH2/-NH- group anion dye from the dye mixture. To provide important clues to the zinc sulfide nanostructures that selectively adsorb some organic dyes. Third, a new method of synthesizing ZnS nanotube /CdS hollow sphere nanocomposites at room temperature is proposed. Only four kinds of low cost raw materials (Zn (CH3COO) 2, Na2CO3, Cd (CH3COO) 2 and Na2S) are used. First, through the two step direct precipitation process, The work was made to synthesize the precursor of the rod /CdCO3 complex. Then the target product ZnS nanotube /CdS hollow sphere composite was synthesized by a simple ion exchange reaction. The whole experiment process was carried out at normal temperature and low requirement for the synthetic equipment. We used this composite as an adsorbent for the organic dye. The adsorption experiment showed that the ZnS/CdS compound was recovered. The selective adsorption of anionic dyes with NH2/NH- is much higher than that of ZnS nanotubes. In addition, the maximum adsorption capacity of ZnS/CdS composites to CR can be as high as 950 mg g-1.. Therefore, this work creates a new idea for the synthesis of hollow composite materials by direct precipitation method at normal temperature, which will have a great reference for the future synthesis of other composite materials. The value also indicates the great potential of hollow composites in the adsorption and treatment of organic dyes.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ424

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