论文标题:无机纳米材料的溶剂热合成与表征
Synthesis and Characterization of Inorganic Nanomaterials by Solvothermal Methods
论文作者
论文导师 胡效亚；张永才,论文学位 硕士,论文专业 分析化学
论文单位 扬州大学,点击次数 135,论文页数 89页File Size17209K
2006-05-01论文网 http://www.lw23.com/lunwen_341105752/
本论文从研究无机纳米材料的第一步——无机纳米材料的制备与表征着手,利用水热与溶剂热法,设计新的反应体系和工艺路线,通过调节反应物种类及其用量、溶剂种类与浓度、反应温度、反应时间等实验参数,很好地实现了亚微米金属晶以及硫化物半导体纳米材料的相、形貌以及尺寸的控制合成,并通过多种测试手段对所得到的产物进行分析与表征。现对本论文的主要内容总结如下: 1.以乙二胺为溶剂,通过在180°C的反应条件下,反应时间为15-20 h,还原CuCl2·2H2O来合成亚微米铜粉,在80-160°C的反应条件下,反应时间为20 h,还原AgNO3来合成亚微米银粉,实验考察了反应温度、反应时间等参数对所得产物性质的影响,并利用X-射线粉末衍射(XRD)、X-射线光电子能谱(XPS)、透射电子显微镜(TEM)等多种现代分析测试手段对所得产物进行了测试与表征。此外,我们还探讨了上述条件下铜和银亚微米晶的形成机理,表明所用溶剂乙二胺既作为还原剂又作为络合剂。 2.通过热分解单分子前驱体Zn-(DDTC)_2制备不同相、形貌以及不同尺寸的ZnS纳米晶体,主要包括以下两步:首先在常温常压下通过二乙基二硫代氨基甲酸钠与醋酸锌的沉淀反应制得单分子前驱体Zn-(DDTC)_2;然后分别采用高温灼烧和溶剂热处理前驱体,前者在空气中280°C灼烧前驱体得到了六方相的ZnS纳米颗粒,后者通过采用不同的反应溶剂(水、无水乙醇、水合肼)、反应温度(150-200°C),以及不同的反应时间(3-48 h),在溶剂热条件下热解单分子前驱体Zn-(DDTC)_2,分别得到了立方和六方两种不同相,以及不同形貌与尺寸的产物,从而很好地实现了ZnS纳米颗粒的相与形貌以及尺寸的控制合成,并利用XRD、XPS、TEM、高分辨透射电子显微镜(HRTEM)、选区电子衍射(SAED)、紫外-可见吸收光谱(UV-Vis)、荧光光谱(PL)等多种现代分析测试手段对所得产物进行了表征。
The present thesis is focused on the first step of inorganic nanomaterials research -- the synthesis and characterization of inorganic nanomaterials. By the adoption of new hydrothermal/solvothermal methods and varying the experimental parameters such as reaction source species and amounts, temperature and time, solvents species and concentration, etc., the shape, size and phase-controlled synthesis of metal submicrocrystallites, and semiconducting metal sulfides (ZnS, CdS) nanocrystals has been achieved. Meanwhile, many techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scan electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), UV-Vis absorption spectra, fluorence spectra, and so on, were used to characterize the as-synthesized products. The main work completed in this thesis can be summarized as the following: 1. Pure submicrometer-sized copper and silver crystallites have been directly synthesized via solvothermal treatment of CuCl2·2H2O or AgNO3 in ethylenediamine (EDA) at 80-180°C for 15-20 h, and characterized by means of X-ray power diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It was suggested that the formation of copper and silver crystallites in this solvothermal system be through a typical complexation–reduction process, in which EDA serves not only as a reducing reagent, but also as a complexing solvent. 2. The phase, shape and size-controlled synthesis of ZnS nanocrystals from an air-stable single-source molecular precursor (zinc diethyldithiocarbamate: Zn-(DDTC)_2) has been achieved by two facile steps: firstly, the Zn-(DDTC)_2 precursor was prepared directly through the precipitation reaction of zinc acetate and sodium diethyldithiocarbamate in distilled water under ambient condition; secondly, pure cubic
|
