【作者】 吴铎；

【导师】 满石清；

【作者基本信息】 暨南大学 ， 物理电子学， 2010， 硕士

【摘要】 相对于体材料,纳米尺寸的金属粒子(如Au、Ag、Cu等)具有独特的光学、电学、磁学、力学和催化特性,在许多领域有着广阔的应用前景,如癌症治疗、生物传感、纳米光学器件、表面增强荧光光谱和表面增强拉曼散射等方面。在金属纳米粒子众多特性中,表面等离子共振(SPR)特性是研究的热点之一。玻璃中的金属纳米粒子由于其表面等离子共振,在特征峰附近会出现明显的光学非线性现象。影响表面等离子共振的因素包括纳米粒子的尺寸、形状、介电性质以及周围的介质环境。其中,纳米粒子的形貌是影响这些特性的主要因素之一,因而制备不同形貌的金属纳米粒子越来越受到人们的广泛关注本文采用水热法和离子交换结合热处理法制备不同形貌的Cu纳米粒子。通过扫描电子显微镜(SEM)、X射线衍射分析仪(XRD)、紫外-可见(UV-Vis)分光光度计和荧光分光光谱仪对Cu纳米粒子的表面形貌、晶体结构及光学性质进行了表征和研究。SEM结果表明所制备的Cu纳米粒子粒径分布范围窄,单分散性良好；XRD结果表明,以水热法制备的Cu纳米粒子结晶程度较好,出现了对应于Cu面心立方(fcc)晶系的(111)、(200)和(220)晶面的衍射峰,而离子交换结合热处理法制备的Cu纳米粒子可能由于部分被氧化,只出现强度较弱的(111)晶面择优取向峰；荧光光谱仪分析表明,当激发光波长λex为270 nm时,其发射光λem分别为370 nm和500 nm。当激发光波长λex为560 nm时,其发射光λem为800 nm；UV-Vis吸收光谱表明,Cu纳米粒子的表面等离子体共振峰随离子交换时间的延长以及退火温度的升高而红移。更多还原

【Abstract】 Compared to the bulk elements, nano-sized metal nanoparticles exhibit unique optical, electrical, magnetic, mechanical and catalytic properties. Based on their unique properties, metal nanoparticles have been widely applied in the fields of cancer therapeutics, biological sensors, nanoscale optical devices, surface-enhanced fluorescence and surface-enhanced raman spectroscopies. The surface plasmon resonance (SPR) is one of the most concerned research focus among all these properties. The optical nonlinear phenomena could be observed obviously around the absorption peak, due to the surface plasmon resonance. The SPR is very sensitive to the size, shape, dielectric properties of the nanoparticles and dielectric environment. Synthesizing metal nanoparticles with different morphologies has received more attention, because the morphology of nanoparticles is one of the main factors affecting the features.Copper nanoparticles embedded in BK7 glasses have been prepared with hydrothermal method and ion-exchange method following by reducing in H2, respectively. Their surface morphologies, crystal structures, and optical properties have been characterized and investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis absorption and fluorescence (FL) spectrophotometers.SEM images showed that the prepared copper nanoparticles were uniform in size distribution and had a good monodispersity. XRD results revealed that the Cu nanoparticles prepared by hydrothermal method were found to be good crystalline. The peaks showed in the picture corresponded to the formation of Cu (111), (200) and (220) nanocrystals. However, those prepared by ion-exchange method might be oxidized partially and displayed only a weak preferential (111) orientation. It was found by the fluorescence spectrophotometers that the copper ions displayed two emission band at 370 nm and 500 nm for the excitation at 270 nm. Meanwhile, the luminescence at 800 nm attributed to the excitation at 560 nm. UV-Vis absorption spectra indicated that the SPR peaks showed a red shift with increase of the ion-exchanged time and the reducing temperature.更多还原