【摘要】：納米銀作為一種貴金屬納米材料愈來愈備受關(guān)注,其具有的與塊狀金屬不同的特殊的化學(xué)和物理性質(zhì)使得其在光化學(xué)、電化學(xué)、生物醫(yī)學(xué)和工業(yè)催化等領(lǐng)域都得到了廣泛的應(yīng)用。然而,納米銀的形貌和尺寸大小與它表現(xiàn)出的各種性能是息息相關(guān)的。所以,當(dāng)今的研究熱點(diǎn)之一就是對(duì)納米銀的形貌進(jìn)行可控制備。目前,納米銀在其形貌的可控合成方面取得的成就仍然比較有限�；诖�,本文分別利用反相微乳液法和液相化學(xué)還原法成功制備了多種形貌的貴金屬納米銀粒子,探索出了一種簡(jiǎn)易的一步合成銀納米線的方法。此方法區(qū)別于以往文獻(xiàn)中報(bào)道的銀納米線合成過程中需慢慢滴加注入反應(yīng)液這一過程。反應(yīng)物一次性溶解,無(wú)需控制滴加速度,使得操作更加簡(jiǎn)單易行,適合大規(guī)模生產(chǎn)。另外,據(jù)文獻(xiàn)報(bào)道,經(jīng)過納米銀負(fù)載的半導(dǎo)體如ZnO的光學(xué)性能,抗菌性能等都有很大的改善,鑒于此,本文又利用光照還原法成功合成了Ag-ZnO的納米棱柱復(fù)合陣列。本論文的研究工作主要內(nèi)容如下：利用反相微乳液法,以二丁酸二辛酯磺酸鈉充當(dāng)表面活性劑、異辛烷為溶劑自發(fā)形成的W/O型微乳液體系中,分別以AgNO3和抗壞血酸為銀源和還原劑,制備了尺寸均勻,無(wú)任何團(tuán)聚現(xiàn)象,單分散性非常好的球形納米銀顆粒。用液相化學(xué)還原法,將N,N二甲基甲酰胺(DMF)作為溶劑兼還原劑,以聚乙烯吡咯烷酮(PVP)作為表面活性劑,通過調(diào)控改變相關(guān)實(shí)驗(yàn)條件,可控制備了銀的三角形、六邊形納米片和十面體混合物,銀的六角多面體,六邊形納米銀片以及鏈狀和線狀A(yù)g的形貌結(jié)構(gòu)。實(shí)驗(yàn)結(jié)果表明,溶液中AgNO3與PVP的濃度比是決定合成Ag最終形貌的關(guān)鍵。除此之外,為了研究不同的還原劑對(duì)合成的銀形貌結(jié)構(gòu)的影響,我們用乙二醇(EG)代替DMF作為溶劑和還原劑,通過改變實(shí)驗(yàn)條件,同樣在油浴鍋中以相同的溫度還原AgNO3,制備了不同形貌的納米Ag晶,包括單分散的Ag六角多面體和納米Ag線。探索出了一種簡(jiǎn)易的一步合成銀納米線的方法。將上述實(shí)驗(yàn)制備的各種形貌的納米銀應(yīng)用于催化亞甲基藍(lán)的還原實(shí)驗(yàn)。結(jié)果表明：用液相還原法合成的多形貌納米銀都有很好的催化性能,其中,六角多面體納米銀晶的催化效果最好。進(jìn)一步探討了不同銀用量對(duì)于亞甲基藍(lán)還原效果的影響,以及可能的催化反應(yīng)機(jī)理。而在亞甲基藍(lán)的還原反應(yīng)實(shí)驗(yàn)中,用反相微乳液法合成的納米銀顆粒沒有表現(xiàn)出明顯的催化性能。以氧化鋅納米柱為載體,用先浸泡吸附后光照還原的方法在氧化鋅納米柱表面均勻負(fù)載了銀納米顆粒,成功合成了Ag-ZnO的納米棱柱復(fù)合陣列,此合成方法能準(zhǔn)確控制貴金屬的沉積量和金屬顆粒的大小,且操作簡(jiǎn)單易行。
[Abstract]:As a kind of precious metal nanomaterials, nano-silver has attracted more and more attention. Its special chemical and physical properties are different from bulk metals, which make it in photochemistry and electrochemistry. Biomedicine and industrial catalysis have been widely used. However, the morphology and size of silver nanoparticles are closely related to their various properties. Therefore, one of the research hotspots is to control the morphology of silver nanoparticles. At present, the achievements of nano-silver in the controllable synthesis of its morphology are still limited. Based on this, silver nanoparticles with various morphologies were successfully prepared by reverse microemulsion method and liquid phase chemical reduction method, and a simple one-step method of silver nanowires synthesis was explored. This method is different from the process of silver nanowires synthesis reported in the past. The reactant dissolved in one-time, without controlling droplet acceleration, makes the operation easier and more suitable for mass production. In addition, it has been reported that the optical properties and antibacterial properties of nano-silver supported semiconductors such as ZnO have been greatly improved. In view of this, we have successfully synthesized the nano-prism composite arrays of Ag-ZnO by the method of light reduction. The main contents of this thesis are as follows: in the W / O microemulsion system, sodium dioctyl dibutyrate was used as surfactant and isooctane as solvent by reverse microemulsion method. Using AgNO3 and ascorbic acid as silver source and reducing agent, spherical silver nanoparticles with uniform size, no agglomeration and very good monodispersity were prepared. The triangulation of silver can be controlled by changing the experimental conditions by liquid phase chemical reduction method, using N-dimethylformamide (DMF) as solvent and reductant, polyvinylpyrrolidone (PVP) as surfactant. The morphology and structure of hexagonal and decahedron, hexagonal polyhedron, hexagonal silver sheet and chain and linear Ag. The experimental results show that the concentration ratio of AgNO3 to PVP is the key to determine the final morphology of synthesized Ag. In addition, in order to study the effect of different reductants on the morphology and structure of synthesized silver, we used ethylene glycol (EG) instead of DMF as solvent and reductant. By changing the experimental conditions, we also reduced AgNO3, at the same temperature in oil bath pot. Nanocrystalline Ag crystals with different morphologies were prepared, including monodisperse Ag hexagonal polyhedrons and nanocrystalline Ag wires. A simple one-step method for the synthesis of silver nanowires has been developed. The nano-silver with various morphologies was used to catalyze the reduction of methylene blue. The results show that the polymorphic nanocrystalline silver synthesized by liquid phase reduction method has good catalytic performance, among which hexagonal polyhedron nanocrystalline has the best catalytic effect. The effect of different amount of silver on the reduction of methylene blue and the possible mechanism of catalytic reaction were discussed. However, in the reduction experiment of methylene blue, the silver nanoparticles synthesized by inverse microemulsion method showed no obvious catalytic activity. Silver nanoparticles were uniformly loaded on the surface of zinc oxide nanocrystals by immersion adsorption and light reduction method, and Ag-ZnO nano-prism composite arrays were successfully synthesized. This synthetic method can accurately control the deposition amount of precious metals and the size of metal particles, and is easy to operate.
【學(xué)位授予單位】：華中師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：O614.122;TB383.1

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本文編號(hào)：2397241