發(fā)布時(shí)間：2019-05-12 12:03

【摘要】：銅(Cu)納米結(jié)構(gòu)因其具有優(yōu)異的導(dǎo)電、導(dǎo)熱和延展性,且Cu價(jià)格低廉、儲(chǔ)量豐富,在柔性透明電極、太陽(yáng)能電池、催化劑等領(lǐng)域具有重要的應(yīng)用潛能。本論文圍繞Cu納米線、Cu納米立方體和Cu納米四面體的制備及其光學(xué)特性開展實(shí)驗(yàn)和理論研究,并借助FDTD數(shù)值計(jì)算分析Cu納米立方體的Cu納米四面體的光吸和散射光譜,研究結(jié)果為基于Cu納米結(jié)構(gòu)的相關(guān)理論與應(yīng)用研究奠定基礎(chǔ)。本論文的具體研究?jī)?nèi)容和研究成果如下:1.基于液相還原法制備了直徑均勻的五重孿晶Cu納米線。研究溶劑熱反應(yīng)溫度、還原劑濃度和表面包覆劑種類對(duì)Cu納米線生長(zhǎng)的影響。對(duì)比研究了十六胺(HDA)、十八胺(ODA)與Cu2+之間的絡(luò)合物的紫外-可見(jiàn)(UV-Vis)吸收光譜,進(jìn)而揭示出Cu納米線的生長(zhǎng)機(jī)制。結(jié)果表明:烷基胺與Cu2+首先形成了銅胺絡(luò)合物,該絡(luò)合物在高溫高壓條件下被還原為Cu原子;提高溶劑熱反應(yīng)溫度或增加還原劑濃度都能夠加快還原反應(yīng)速率,使納米晶體迅速成核,繼而生長(zhǎng)成為五邊形雙錐體結(jié)構(gòu)或鉛筆狀納米晶體;改變烷基胺種類,將HDA分別更換為ODA和油胺(OLA)也可以制備出Cu納米線,但納米線的直徑較大。2.基于烷基胺的水熱合成法成功制備出尺寸在一定范圍內(nèi)可調(diào)的Cu納米立方體和四面體結(jié)構(gòu)。通過(guò)提高絡(luò)合反應(yīng)溫度、調(diào)整配體(單一配體或雙配體)的種類及比例,獲得不同形貌及結(jié)構(gòu)的Cu納米晶體,并結(jié)合動(dòng)力學(xué)和熱力學(xué)理論,解釋了Cu納米四面體和立方體的生長(zhǎng)機(jī)制。實(shí)驗(yàn)結(jié)果表明:通過(guò)改變絡(luò)合反應(yīng)溫度而調(diào)整銅胺絡(luò)合物的濃度,可有效控制納米晶體的形貌;降低兩種配體(HDA和ODA)的比值,制備的納米多面體的尺寸在100~600 nm范圍不斷增加。本工作的意義在于首次提出了Cu納米四面體的制備方法,為以后的Cu基納米結(jié)構(gòu)的理論及實(shí)驗(yàn)研究奠定基礎(chǔ)。3.利用時(shí)域有限差分(FDTD)方法模擬單個(gè)Cu納米立方體和四面體的吸收及散射光譜,并對(duì)Cu納米多面體在水溶液和固體粉末狀態(tài)下的吸收和散射光譜加以討論。實(shí)驗(yàn)測(cè)得的UV-Vis光譜是不同尺寸Cu納米立方體和四面體的吸收光譜按照一定比率的疊加的平均效果。其中,600 nm附近的共振吸收主要來(lái)自于Cu納米立方體,而750~950 nm寬帶吸收主要是Cu納米四面體的共振吸收。
[Abstract]:Copper (Cu) nanostructures have important application potential in flexible transparent electrodes, solar cells, catalysts and other fields because of their excellent conductivity, heat conduction and extensibility, low price and rich reserves of Cu. In this paper, the preparation and optical properties of Cu nanowires, Cu nano-cubes and Cu nano-tetrahedral are studied experimentally. the optical absorption and scattering spectra of Cu nano-tetrahedral of Cu nano-cube are analyzed by FDTD numerical calculation. The results lay a foundation for the theory and application of Cu nanostructures. The specific research contents and results of this paper are as follows: 1. Five twin Cu nanowires with uniform diameter were prepared by liquid phase reduction method. The effects of solvothermal reaction temperature, reductant concentration and surface coating agent on the growth of Cu nanowires were studied. The UV-vis (UV-Vis) absorption spectra of the complex between hexadecylamine (HDA), octadecylamine (ODA) and Cu2 were studied, and the growth mechanism of Cu nanowires was revealed. The results show that alkylamine first forms a copper amine complex with Cu2, which is reduced to Cu atom at high temperature and high pressure. Increasing the solvothermal reaction temperature or increasing the concentration of reductant can accelerate the reduction reaction rate and make the nanocrystals nucleate rapidly, and then grow into pentagonal bipyramidal or pencil-like nanocrystals. Cu nanowires can also be prepared by changing the type of alkyl amines by replacing HDA with ODA and oleoamine (OLA), respectively, but the diameter of nanowires is larger. 2. Cu nanocubes and tetrahedral structures with adjustable size were successfully prepared by hydrothermal synthesis based on alkyl amines. By increasing the temperature of complexation reaction and adjusting the type and proportion of ligands (single ligand or double ligand), Cu nanocrystals with different morphology and structure were obtained, and combined with kinetics and thermodynamic theory, The growth mechanism of Cu nano-tetrahedral and cube is explained. The experimental results show that the morphology of nanocrystals can be effectively controlled by adjusting the concentration of copper amine complex by changing the temperature of complexation reaction. By reducing the ratio of the two ligands (HDA and ODA), the size of the prepared nano-polyhedral increases in the range of 100 鈮，

本文編號(hào)：2475378