金納米顆粒的可控制備及其光學(xué)性能研究
發(fā)布時間:2018-02-07 09:03
本文關(guān)鍵詞: 局域表面等離激元 表面增強拉曼散射 金納米棒 金納米雙錐 Au@Cu_2O異質(zhì)結(jié)復(fù)合結(jié)構(gòu) 出處:《湖北工業(yè)大學(xué)》2017年碩士論文 論文類型:學(xué)位論文
【摘要】:金納米顆粒表現(xiàn)出很強的表面等離子體共振效應(yīng)(Localized surface plasmon resonance,LSPR),其吸收峰的位置與納米顆粒的幾何形狀,核殼結(jié)構(gòu),大小以及周圍介質(zhì)有關(guān)。雖然LSPR能夠監(jiān)測到吸附在金納米顆粒表面的分析物分子,但是消光光譜并不能夠識別吸附分子結(jié)構(gòu)的整體特征,而振動光譜卻可以彌補這一不足。表面增強拉曼光譜(Surface-enhanced Raman spectroscopy,SERS)能夠顯示出分子的特征振動圖譜且不會損壞分析物的結(jié)構(gòu)。通過將LSPR與SERS兩種技術(shù)聯(lián)用,可以獲取分析物的定量和定性信息。非球形金納米顆粒通過改變其尺寸和形狀能實現(xiàn)可見和紅外波段的連續(xù)可調(diào)諧,并與不同激發(fā)波長的檢測目標相匹配等優(yōu)勢而受到廣泛關(guān)注。在本論文中,我們設(shè)計與合成了不同結(jié)構(gòu)的金納米顆粒,探索了金納米顆粒在分子檢測方面的應(yīng)用;另外制備了Au@Cu_2O異質(zhì)結(jié)復(fù)合結(jié)構(gòu),并利用該結(jié)構(gòu)在光催化降解方面進行了研究。主要內(nèi)容如下:1.金納米顆粒的調(diào)控及其在SERS中的應(yīng)用研究(1)采用水相合成法制備了一系列不同長徑比的金納米棒結(jié)構(gòu),金納米棒的長徑比主要通過硝酸銀和種子溶液的含量來調(diào)節(jié),并且通過調(diào)節(jié)長徑比可精確調(diào)控其對應(yīng)的LSPR峰。實驗分別以不同LSPR的金納米棒為基底,采用LSPR與SERS聯(lián)用技術(shù)來測定拉曼分子,并分析了LSPR與SERS之間的關(guān)聯(lián)效應(yīng);實驗和理論結(jié)果表明金納米棒對于拉曼分子的測定具有較高的靈敏度,當LSPR與拉曼激發(fā)波長相匹配時,增強效果可以達到10-7 mol/L。(2)采用金納米棒作為種子溶液,有效實現(xiàn)金納米顆粒從棒狀到截角八面體再到八面體的系統(tǒng)性形狀演化。此種橫向生長模式為金納米棒調(diào)整消光截面和縱向等離子體波長提供了可選擇方式,這將促進其作為新材料在生物技術(shù)、光電子學(xué)和光學(xué)等領(lǐng)域的應(yīng)用。(3)制備了均勻性較高的金納米雙錐結(jié)構(gòu),并以此為基礎(chǔ)合成了金核銀殼納米棒結(jié)構(gòu),分別以它們?yōu)榛滋骄苛藘煞N結(jié)構(gòu)對SERS的增強效應(yīng)。實驗和理論結(jié)果表明金納米雙錐具有一個五邊形基底和兩個尖銳的頂點,產(chǎn)生了新的額外“熱點”。因此,與金納米棒相比,金納米雙錐對周圍的折射率更加靈敏,局域電場增強效應(yīng)更強。該材料可以應(yīng)用于生物活體內(nèi),對今后癌細胞的檢測有著巨大的潛力。2.Au@Cu_2O異質(zhì)結(jié)復(fù)合結(jié)構(gòu)的制備及其在光催化降解中的應(yīng)用研究實驗制備了Au@Cu_2O異質(zhì)結(jié)復(fù)合結(jié)構(gòu),探究了Cu_2O立方體生長的機理以及表面活性劑的必要性,并討論了外層Cu_2O對內(nèi)部金納米棒吸收譜的影響。最后,將Cu_2O立方體結(jié)構(gòu)和Au@Cu_2O復(fù)合結(jié)構(gòu)用于降解羅丹明B研究,實驗結(jié)果表明Au@Cu_2O異質(zhì)結(jié)復(fù)合結(jié)構(gòu)光降解能力要強于Cu_2O立方體結(jié)構(gòu)。本論文較系統(tǒng)地研究了金納米顆粒結(jié)構(gòu)中的表面等離激元激發(fā)引發(fā)的局域電場增強效應(yīng)與微結(jié)構(gòu)之間的關(guān)系,進而通過設(shè)計金納米結(jié)構(gòu)的幾何參數(shù)來調(diào)節(jié)表面等離激元共振,實現(xiàn)高SERS效應(yīng)并能滿足特定應(yīng)用需求金納米顆粒的可控制備,為進一步開發(fā)金納米顆粒的應(yīng)用提供了理論和實驗基礎(chǔ)。
[Abstract]:Gold nanoparticles exhibit strong surface plasmon resonance effect (Localized surface plasmon resonance, LSPR), the position of the absorption peak and nano particle geometry, core-shell structure, size and the surrounding medium. Although LSPR can detect the analyte molecules adsorbed on the surface of gold nanoparticles, but not to the overall extinction spectrum feature recognition of adsorption of molecular structure, and vibrational spectra can compensate for this deficiency. The surface enhanced Raman spectrum (Surface-enhanced Raman, spectroscopy, SERS) can show the characteristics of molecular vibration and will not damage the structure of analytes. By LSPR and SERS two kinds of technique, can obtain the quantitative and qualitative information analysis non spherical gold nanoparticles with tunable change its size and shape to achieve the visible and infrared wavelengths, and with different excitation wavelength. The target of matching advantage and attracted widespread attention. In this thesis, we designed and synthesized gold nanoparticles of different structure, explores the application of gold nanoparticles in molecular detection; in addition to preparation of Au@Cu_2O heterojunction composite structure, and carried out the research on photocatalytic degradation by the structure. The main contents are as follows: 1. Study on the regulation of gold nanoparticles and its application in SERS (1) using the aqueous preparation of a series of different aspect ratio of gold nanorods structure, the aspect ratio of gold nanorods to adjust the main content by silver nitrate and seed solution, and by adjusting the aspect ratio adjust the corresponding LSPR peak. The experiment with different LSPR gold nanorods as the base, combined with technology to measure the Raman molecular by LSPR and SERS, and analyzes the correlation effect between LSPR and SERS; the theoretical and experimental results show that the Gold nanorods have high sensitivity for the determination of Raman molecules, when LSPR and Raman excitation wavelength, enhancement effect can reach 10-7 mol/L. (2) using gold nanorods as seed solution, the effective realization of system of shape of gold nanoparticles from rod to truncated eight surface to the eight surface body evolution provides. The choice of the lateral growth mode for the adjustment of gold nanorods extinction cross section and longitudinal plasma wavelength, which will promote it as a new material in bio technology, optoelectronics and optical applications. (3) high uniformity of gold bipyramids structure were prepared, and the Au core Ag shell nanorods were synthesized based on structure in their basement, respectively explores the enhancement effect of two kinds of structure of SERS. The experimental and theoretical results show that the nano gold double cone has a Pentagon base and two sharp vertices, the Additional "hot" new. Therefore, compared with the gold nanorods, gold bipyramids to the surrounding refractive index is more sensitive, local field enhancement effect is stronger. The material can be applied to in vivo detection of cancer cells in the future, has a huge potential of.2.Au@Cu_2O heterojunction composite structure preparation and light study on the application of photocatalytic degradation experimental preparation of Au@Cu_2O heterojunction composite structure, to explore the mechanism of Cu_2O cube growth and necessity of surfactant, and discusses the influence of Cu_2O on the absorption spectrum of the outer layer inside the gold nanorods. Finally, the Cu_2O cube structure and Au@Cu_2O composite structure for the degradation of rhodamine B, the experimental results show that Au@Cu_2O heterojunction composite structure stronger photocatalytic ability in Cu_2O cubic structure. This paper systematically studies the structure of gold nanoparticles in the surface plasmon excitation induced by The relationship between the effect and the micro structure of the local electric field enhancement, and then through the design of geometric parameters of gold nanostructures to regulate surface plasmon resonance, high SERS effect and can meet the requirements of a specific application controlled synthesis of gold nanoparticles, provides theoretical and experimental basis for further development and application of gold nanoparticles.
【學(xué)位授予單位】:湖北工業(yè)大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2017
【分類號】:TQ131.23;TB383.1
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本文編號:1494009
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