QQ客服 官方微博 反馈留言

题名	发光金属（Au、Ag、Cu、Pt）团簇的合成及其性能研究
作者	周劭臣
学位类别	硕士
答辩日期	2016-05-24
授予单位	中国科学院大学
授予地点	北京
导师	王传义
关键词	金属纳米簇 团簇 荧光 检测 催化
学位专业	材料物理与化学
中文摘要	发光金属团簇是一种由几个到几十个过渡金属原子（如Au、Ag、Cu、Pt、Pd等）组成，具有明显光致发光性质的小尺寸材料（粒径<3 nm）。发光金属团簇的性质介于原子金属和金属纳米粒子之间，是这两类物质的中间“过渡态”。金属团簇因其优异的光致发光性质、高活性的催化能力近年来吸引了研究者们的广泛关注，在各类化学催化反应过程、生物和化学检测、荧光成像标记等领域表现出巨大的应用潜力和研究价值。然而，鉴于极小的尺寸产生的高表面活性，金属团簇极易聚集和氧化，因此发光金属团簇的制备一直是一项具有挑战性的工作。在本论文中，采用了两种化合物，3-巯基丙基三甲氧基硅烷和还原性组氨酸作为稳定剂，分别制备了醇溶性的发光硅烷-金纳米簇，硅烷-铜团簇，以及水溶性的发光组氨酸-铂、金、银、铜团簇。论文研究内容和结果主要分为以下三个方面：（1）采用3-巯基丙基三甲氧基硅烷作为稳定剂，通过一种简单、有效的光化学方法成功制备了粒径及荧光性质均不相同的金纳米簇，实现了对所获得的金团簇荧光和粒径的调控。荧光光谱和高分辨透射电镜结果显示：平均粒径分别为1.3 nm、1.8 nm 以及 2.0 nm的金纳米簇，其荧光发射波长分别为538 nm、558 nm和580 nm。另外，硅烷-金纳米簇具有类似于半导体的特性，如紫外-吸收光谱中出现吸收边的性质等。有趣的是，本工作所制备的硅烷-金纳米簇也具有一定的光催化能力，可以作为独立光催化剂参与光催化反应。在可见光的照射下，硅烷-金纳米簇能有效促进亚甲基蓝的降解反应，60分钟的照射时间里亚甲基蓝的降解率达到95.6%。这个发现也进一步拓展了金纳米簇在催化领域的应用范围。（2）同样采用3-巯基丙基三甲氧基硅烷作为稳定剂，利用其巯基官能团与铜较强的亲和力，以及氰基硼氢化钠适中的还原能力，通过还原铜盐生成硅烷保护的铜团簇粒子。质谱分析结果显示硅烷-铜团簇基本由4-9个铜原子组成，并在波长为375 nm紫外光激发下会发射出峰位置分别位于410 nm和580 nm的双峰荧光。紫外-可见吸收光谱分析结果显示硅烷-铜团簇也具有半导体类似的吸收边特性。该发光铜团簇具有良好的光稳定性，在365 nm紫外光连续照射120分钟后荧光强度降低仅5%。另外，硅烷-铜团簇拥有优异的荧光检测能力，对低浓度的双氧水十分敏感，能在5-250μM范围内对其线性响应，可以用作双氧水的荧光探针。另一方面，该硅烷-铜团簇能够有效催化亚甲基蓝的化学还原形成亚甲基白以及光催化亚甲基白的氧化过程，实现可逆的光致变色体系，为铜团簇的应用开辟了新的领域。（3）用还原性组氨酸作为稳定剂，抗坏血酸作还原剂，发展了一种通用、简单、绿色、快速的方法成功制备了组氨酸-铂、金、银、铜团簇。该方法完全无毒无害，条件温和且快速，生成的金属团簇尺寸分布均一，拥有良好的发光效率。经测试，组氨酸-铂、金、银、铜团簇的发光效率分别为2.93%、13.10%、6.97%和8.29%。高分辨透射电镜表征结果显示铂、金、银、铜团簇的平均粒径分别为 1.9、1.8、1.3和1.7 nm，而电喷雾质谱结果显示它们主要由Pt11、Au9、Ag4和Cu7组成。有趣的是，四种所制备的金属团簇都对水相铁离子具有高的选择性响应，可以同时作为比色传感器以及荧光传感器，对水体中微量铁离子进行检测，使其在生物检测领域有着较大的应用潜力。
英文摘要	Luminescent metal clusters，composed of several to dozens of transition metal atoms (Au, Ag, Cu, Pt, Pd), are ultra-small sized materials (particle size<3 nm) with excellent photoluminescence properties, possessing a nature that bridges the gap between both metal atoms and nanoparticles. In recent years, these metal clusters have attracted great attention because of their excellent photoluminescence property and high catalytic activity, showing significant application potentiality and research value in various chemical catalysis processes, chemical detection as well as biological imaging and labeling. However, due to the extremely high surface activity arising from small size, metal clusters are highly prone to aggregation and oxidation, making their preparation rather challenging. In this thesis, two compounds, namely 3-mercaptopropyl trimethoxysilane and histidine, were utilized as protecting stabilizers in the synthesis of ethanol-soluble gold, copper clusters, and water-soluble platinum, gold, silver, copper clusters, respectively. Specifically, the thesis work covers the following three parts：(1) A simple and effective photochemical method by applying 3-mercaptopropyl trimethoxysilane as stabilizer is developed to prepare various sized and fluorscent gold clusters, whose fluorescence color and particle size are tunable. Fluorescence spectra and HRTEM results show that Au clusters with average size of 1.3 nm, 1.8 nm and 2.0 nm give emission bands centered at 538 nm, 558 nm and 580 nm, respectively. In addition, the silane-capped gold clusters have some semiconductor-like features, such as the absorption edge in their UV-vis absorption spectra. Interestingly, the as-prepared gold nanoclusters are found to possess decent photocatalytic activity and are capable of being ultilized as an independent photocatalyst. Under visible light irradiation, these silane-capped gold clusters can effectively promote the degradation of methylene blue, with degradation efficiency of 95.6% in 60 minutes. This work has further broadened the Au clusters’ application as efficient catalysts.(2) Due to the strong affinity between mercapto groups and copper as well as the apporpiate reducing capacity of sodium cyanoborohydride, silane-capped copper clusters are produced by using 3-mercaptopropyl trimethoxysilane as stabilizer, through a wet chemical reduction method. Mass spectra show that the silane-capped copper clusters mainly consist of 4-9 copper atoms, which emit a special fluorescence with two emission bands centered at 410 nm and 580 nm under UV excitation at 375 nm. UV-vis absorption spectral characterization suggests that the silane-capped copper clusters also have semiconductor-like properties like absorption edge. And the as-synthesized copper clusters exhibit decent photostability, whose fluorescence intensity decreased by only 5% after 120 minutes of continuous UV irradiation at 365 nm. In addition, the silane-capped copper clusters possess superior fluorescent detecting capability, linearly responding to hydrogen peroxide in the low concentration range of 5-250 μM, and potentially applicable as a fluorescent probe for H2O2. On the other hand, the silane-capped copper clusters can effectively catalyze reduction of methylene blue and photocatalyze oxidation of leuco methylene blue, forming a photo-reversible color switching system. This work has opened up new application fields for copper clusters. (3) Using histidine as a stabilizer and ascorbic acid as a reducing agent, a universal, simple, green and rapid synthetic method is developed to successfully prepare platinum, gold, silver, copper clusters. The method is completely non-toxic, mild and fast, effective in producing mono-dispersed metal clusters with decent quantum yields, which are 2.93%, 13.10%, 6.97% and 8.29% for the histidine-capped platinum, gold, silver, copper clusters , respectively. High-resolution transmission electron microscopic images evince that platinum, gold, silver, copper clusters have average sizes of 1.9, 1.8, 1.3 and 1.7 nm, respectively. And electrospray ionization mass spectrometry results show that they are mainly composed of Pt11, Au9, Ag4 and Cu7 clusters. Interestingly, all the as-prepared metal clusters are found to be highy selective and sensitive in detecting aqueous ferric ions, both as colorimetric and fluorescent sensors, holding tremendous application potentiality in biological sensing.
内容类型	学位论文
源URL	[http://ir.xjipc.cas.cn/handle/365002/4557]
专题	新疆理化技术研究所_环境科学与技术研究室
作者单位	中国科学院新疆理化技术研究所
推荐引用方式 GB/T 7714	周劭臣. 发光金属（Au、Ag、Cu、Pt）团簇的合成及其性能研究[D]. 北京. 中国科学院大学. 2016.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。