关键词： 光纤   表面增强拉曼散射(SERS)探针   Ag纳米颗粒   拉曼增强特性  

摘要： 为了分析研究光纤表面增强拉曼散射（SERS）探针的拉曼增强特性,采用简单廉价的化学方法制备Ag纳米颗粒修饰光纤SERS探针,采用罗丹明6G（R6G,Rhodamine 6G）作为探针分子进行了不同浓度R6G溶液（10-7~10-9 M）的拉曼测试实验和浓度为10-6 M的R6G溶液的Time-course SERS Mapping实验,研究了该光纤SERS探针的拉曼增强特性,制备的光纤SERS探针样品检测R6G的极限浓度低至10-9 M;在Time-course SERS Mapping实验中,分析验证了探针分子溶液蒸发过程对光纤SERS探针的拉曼增强特性的影响。研究表明,由于制备的光纤SERS探针对荧光噪声没有抑制作用,导致所测得探针分子的拉曼光谱受探针分子溶液状态、测试方式的极大影响。当溶液充足时（浸泡状态）,所测光谱信号荧光噪声与有效拉曼光谱信号都比较大;在溶液干燥过程中,所测光谱信号荧光噪声与有效拉曼光谱信号都减少,但荧光噪声减小幅度远大于拉曼光谱信号。

关键词： Si纳米线阵列   Ag纳米颗粒   等离子体效应   光催化剂  

摘要： 采用原位还原-金属辅助化学刻蚀法制备表面修饰Ag纳米颗粒的Si纳米线阵列,采用SEM、EM、UV-Vis和电化学工作站等手段进行表征,通过光电化学池研究光催化分解水/甲醇溶液(体积比1∶1)实验,分析修饰不同浓度的Ag纳米颗粒的等离子体效应对Si纳米线阵列光催化分解水效率的影响。结果表明,随着Ag纳米颗粒浓度的增加,Ag纳米颗粒/Si纳米线阵列复合结构的开路电压迅速减小,短路电流先增大后减小,而当Ag纳米颗粒以较小的浓度均匀分布于Si纳米线上时,可得到最高的效率。揭示了Ag纳米颗粒的浓度对Si纳米线阵列光催化性能的影响规律。

关键词： Au-Ag合金纳米颗粒   Ag@Au纳米颗粒  

摘要： 通过改进的Frens法,制备出含金量不同的Au-Ag合金纳米颗粒和Ag@Au纳米颗粒.通过测试,UV-Vis光谱结果表明,Au-Ag合金纳米颗粒只有一个介于Au、Ag峰值之间的等离子体共振峰;且峰值与金的摩尔分数呈线性关系.SEM、TEM结果表明Ag@Au纳米颗粒有约为13 nm的壳层;而Au-Ag合金纳米颗粒没有核壳结构,说明是合金,并且随着Au-Ag合金中Au的成分的逐渐增加,粒径趋于均匀、形貌趋于稳定的类球型.

关键词： COPPER NANOPARTICLES   SCATTERING   OXIDATION  

摘要： The purpose of this communication was to understand localized surface plasmon behavior of a series of Ag-Cu alloy nanoparticles capped by rice-starch and gelatin. The structures of dried powders were investigated with the help of X-ray diffraction. The analysis revealed Ag-rich and Cu-rich phases with maximum solid solubility of Cu similar to 9 atom per cent; 8 atom per cent and Ag similar to 16 atom per cent; 14 atom per cent in rice-starch and gelatin capped samples respectively. Transmission electron microscope was used for knowing the particle size as well as to supplement FCC phase formations of Ag-rich and Cu-rich solid phases arrived at based on X-ray diffraction studies. The UV-Vis spectra of sols were examined for the formation and stability of alloy nanoparticles. The temporal evolution of LSPR curves gave us to assert that the sol is stable for more than two months. Small angle X-ray scattering in the sol state was extensively utilized to understand nature of suspensions in terms of fractals. Such a study is important for having a correlation between LSPR behaviors with those of nanoparticle dispersion in aqueous media. It is believed that this work will be a contribution to the emerging field of plasmonics that include applications in the area of photophysical processes and photochemical reactions. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

关键词： ZnO薄膜   Ag纳米颗粒   离子注入   缺陷   光致发光  

摘要： 采用磁控溅射技术在蓝宝石基底上制备了Zn O薄膜,并对样品在氧气氛下进行了热处理,然后采用不同能量、剂量的Ag离子注入Zn O薄膜中,形成Ag纳米颗粒。利用X射线衍射、光致发光、紫外可见吸收等技术详细地研究了样品的结构与发光性质。结果表明,未注入的Zn O薄膜在380 nm和610 nm处出现发光峰,分别对应Zn O激子峰与深能级缺陷峰。Ag离子注入Zn O样品的激子发光峰增强,并在400 nm和430 nm左右处出现新发光峰,同时深能级缺陷引起的发光峰减弱。在N2气氛下退火处理后,Ag离子注入Zn O样品在400 nm处的发光峰消失,430 nm左右发光峰减弱。Ag离子注入Zn O薄膜中合成了Ag纳米颗粒,观察到了Ag纳米颗粒的等离子共振效应。对Ag纳米颗粒和离子注入产生的缺陷、Zn O发光性质的影响给出了解释。

关键词： β-Ag2Se   β-AgCuSe   纳米颗粒   AgCl前驱体   沉淀法  

摘要： 用AgCl前驱体替代传统AgNO_3,通过简单沉淀法合成β-Ag_2Se和β-AgCuSe纳米颗粒。结果表明:所得β-Ag_2Se和β-AgCuSe纳米颗粒均为斜方晶系结构。随着前驱体AgCl浓度的增加,出现Ag_2S杂质。此外,产物的显微组织观察结果表明,其形状为多面体和卵石状。β-Ag_2Se纳米颗粒因晶粒尺寸较小而具有较高的带隙能量。采用AgCl前驱体能成功制备纯纳米颗粒。因此,此研究对合成β-Ag_2Se和β-AgCuSe纳米颗粒具有应用前景的前驱体是十分有意义的。

关键词： 碳包覆   纳米颗粒   磁控溅射   光吸收  

摘要： 采用磁控溅射成功制备了碳包覆Ag纳米颗粒材料,并利用SEM、TEM及UV-vis等手段研究了其形貌、结构和光学性能。结果表明Ag纳米颗粒被完全包覆在碳颗粒之中。该碳包覆纳米颗粒壳-核结构材料在特定波长处呈现特征吸收性能。

关键词： Fe3O4   Ag   纳米颗粒   催化   对硝基苯甲醛  

摘要： 采用水相共沉淀法,以没食子酸作为还原剂,还原Ag[(NH3)2]+,制备出核壳结构的Fe3O4/Ag磁性纳米颗粒.研究了该磁性纳米颗粒对于对硝基苯甲醛还原反应的催化性能,研究结果显示:在40℃,纳米颗粒浓度为0.08%时,反应的收率可接近97%.同时使用过的纳米颗粒可较为方便地从反应液中分离,经多次循环使用后,催化性能没有明显下降.

关键词： 醋酸纤维素   Ag纳米颗粒   静电纺丝   抗菌性能  

摘要： 采用静电纺丝的方法,并结合紫外还原技术,成功制备了Ag纳米颗粒(AgNPs)-醋酸纤维素(CA)纳米纤维。重点研究了溶剂和AgNO3浓度对纤维形貌和AgNPs的分散性及粒径的影响。结果表明:丙酮、DMAc和水(质量比为7∶2∶1)的混合溶液是纺制AgNPs-CA纳米纤维的合适溶剂,在该溶剂体系下,静电纺丝状况较好,AgNPs的尺寸和分布也较理想;随AgNO3添加量的增加,纳米纤维的直径降低,纤维上AgNPs的数量增加;当AgNO3质量分数为0.5%时,AgNPs-CA纳米纤维对金黄色葡萄球菌和大肠埃希菌都具有很好的抗菌效果。

关键词： OPTICAL-PROPERTIES   SILVER NANOPARTICLES   THIN-FILMS   GOLD   SIZE   ABSORPTION   SPECTROSCOPY   DEPENDENCE   SCATTERING   ALUMINA  

摘要： We studied localized surface plasmon resonances (LSPR) at different compositions, substrate temperatures, and mass thicknesses of Ag-Au alloy nanoparticle films grown by sequential pulsed laser deposition. The LSPRs were pronounced at all compositions of the films grown at high substrate temperature of about 300 degrees C as compared to those grown at room temperature. The alloy formation and composition of the films were determined using X-ray photoelectron and energy dispersive spectroscopy. Films' mass thickness and compositional uniformity along the thickness were determined using X-ray reflectometry and secondary ion mass spectroscopy. Atomic force microscopic analysis revealed the formation of densely packed nanoparticles of increasing size with the number of laser ablation pulses. The LSPR wavelength red shifted with increasing either Au percentage or film mass thickness and corresponding LSPR tuning was obtained in the range of 450 to 690 nm. The alloy dielectric functions obtained from three different models were compared and the optical responses of the nanoparticle films were calculated from modified Yamaguchi effective medium theory. The tuning of LSPR was found to be due to combined effect of change in intrinsic and extrinsic parameters mainly the composition, morphology, particle-particle, and particle-substrate interactions. (C) 2015 AIP Publishing LLC.