【摘要】：貴金屬納米晶因其具有優(yōu)異的催化、電學(xué)和光學(xué)等性能,被廣泛應(yīng)用于各個(gè)領(lǐng)域。由于它們的性能決定于其尺寸、形貌和微觀結(jié)構(gòu),因此,貴金屬納米晶的可控合成十分關(guān)鍵,一直是重要的研究課題。功能小分子(包括離子)與金屬及反應(yīng)介質(zhì)之間存在配位、吸附、極化等多重相互作用,使得其具有調(diào)節(jié)金屬納米晶成核和生長(zhǎng)的能力。因此,利用小分子調(diào)控貴金屬納米晶的形貌成為近年來的研究熱點(diǎn)。本論文主要選擇了乙腈、二惡烷、甲胺等小分子,用于調(diào)控Au、Pt及Pt-Cu合金等納米晶的結(jié)構(gòu),評(píng)估了產(chǎn)物的催化性能,主要包含以下三部分:(1)利用乙腈、二惡烷和鹵素離子的相互作用,有效降低了鹵素離子/O2對(duì)孿晶結(jié)構(gòu)的腐蝕強(qiáng)度,成功合成了 Au截角二十面體(孿晶)納米晶;進(jìn)一步地,將乙腈的保護(hù)作用和甲胺的選擇性吸附和配位能力相結(jié)合,合成了具有高指數(shù)晶面的凹立方體Pt納米晶,進(jìn)而獲得了比商業(yè)Pt/C更高的電催化甲醇氧化活性。(2)在上述實(shí)驗(yàn)基礎(chǔ)上,同樣利用乙腈和甲胺對(duì)金屬離子、金屬及反應(yīng)介質(zhì)之間多重相互作用,通過一鍋煮的方法選擇性地合成了多孔凹多面體及多孔凹八面體Pt-Cu合金納米晶。由于其特殊的結(jié)構(gòu),這兩種納米晶對(duì)電催化甲醇氧化反應(yīng)的面積比活性均高于商業(yè)Pt/C,且多孔凹八面體納米晶的活性更高。(3)利用Cu2+,PtCl62-和PdCl42-取代傳統(tǒng)種子生長(zhǎng)法合成金納米棒所加入的Ag+,并通過調(diào)節(jié)Cu2+, PtCl62-等離子的濃度研究金屬離子對(duì)金納米晶生長(zhǎng)的影響。結(jié)果表明,和Ag+的影響不同,Cu2+等金屬離子的參與可以導(dǎo)致類球形的Cu/Au、多面體Pt/Au等納米顆粒的形成。
[Abstract]:Precious metal nanocrystals have been widely used in various fields because of their excellent catalytic, electrical and optical properties. Because their properties are determined by their size, morphology and microstructure, the controllable synthesis of precious metal nanocrystals is very important and has been an important research topic. There are multiple interactions between functional small molecules (including ions) and metals and reaction media, such as coordination, adsorption, polarization and so on, which makes them have the ability to regulate the nucleation and growth of metal nanocrystals. Therefore, the use of small molecules to regulate the morphology of precious metal nanocrystals has become a hot research topic in recent years. In this paper, acetonitrile, dioxane, methylamine and other small molecules were selected to regulate the structure of Au,Pt and Pt-Cu alloys, and the catalytic performance of the products was evaluated. The catalytic performance of the products included the following three parts: (1) the corrosion strength of halogen ion / O2 to twin structure was effectively reduced by using the interaction of acetonitrile, dioxane and halogen ions, and the Au cross-angled icosahedral (twin) nanocrystals were successfully synthesized. Furthermore, concave cubic Pt nanocrystals with high index crystal plane were synthesized by combining the protective effect of acetonitrile with the selective adsorption and coordination ability of methylamine, and the electrocatalytic activity of methanol oxidation was higher than that of commercial Pt/C. (2) on the basis of the above experiments, the multiple interactions between acetonitrile and methylamine on metal ions, metals and reaction media were also used. Porous concave polyhedral and porous concave octahedral Pt-Cu alloy nanocrystals were selectively synthesized by one pot cooking. Because of their special structure, the area specific activity of these two nanocrystals for electrocatalytic methanol oxidation is higher than that of commercial Pt/C, and porous concave octahedral nanocrystals. (3) Cu2, PtCl62- and PdCl42- are used to replace the Ag added to gold nanorods by traditional seed growth method, and the effect of metal ions on the growth of gold nanoparticles is studied by adjusting the concentration of Cu2 and PtCl62- plasma. The results show that, different from the influence of Ag, the participation of metal ions such as Cu2 can lead to the formation of spherical Cu/Au, polyhedral Pt/Au and other nanoparticles.
【學(xué)位授予單位】：溫州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36;TB383.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Yugang Sun;;Interfaced heterogeneous nanodimers[J];National Science Review;2015年03期

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本文編號(hào)：2500781